A blog (a truncation of "weblog")^[1] is a discussion or informational website published on the World Wide Web consisting of discrete, often informal diary-style text entries (posts). Posts are typically displayed in reverse chronological order, so that the most recent post appears first, at the top of the web page. Until 2009, blogs were usually the work of a single individual, occasionally of a small group, and often covered a single subject or topic. In the 2010s, "multi-author blogs" (MABs) emerged, featuring the writing of multiple authors and sometimes professionally edited. MABs from newspapers, other media outlets, universities, think tanks, advocacy groups, and similar institutions account for an increasing quantity of blog traffic. The rise of Twitter and other "microblogging" systems helps integrate MABs and single-author blogs into the news media. Blog can also be used as a verb, meaning to maintain or add content to a blog.

The emergence and growth of blogs in the late 1990s coincided with the advent of web publishing tools that facilitated the posting of content by non-technical users who did not have much experience with HTML or computer programming. Previously, a knowledge of such technologies as HTML and File Transfer Protocol had been required to publish content on the Web, and early Web users therefore tended to be hackers and computer enthusiasts. In the 2010s, the majority are interactive Web 2.0 websites, allowing visitors to leave online comments, and it is this interactivity that distinguishes them from other static websites.^[2] In that sense, blogging can be seen as a form of social networking service. Indeed, bloggers do not only produce content to post on their blogs, but also often build social relations with their readers and other bloggers.^[3] However, there are high-readership blogs which do not allow comments.

Many blogs provide commentary on a particular subject or topic, ranging from politics to sports.

Others function as more personal online diaries, and others function more as online brand advertising of a particular individual or company. A typical blog combines text, digital images, and links to other blogs, web pages, and other media related to its topic. The ability of readers to leave publicly viewable comments, and interact with other commenters, is an important contribution to the popularity of many blogs. However, blog owners or authors often moderate and filter online comments to remove hate speech or other offensive content. Most blogs are primarily textual, although some focus on art (art blogs), photographs (photoblogs), videos (video blogs or "vlogs"), music (MP3 blogs), and audio (podcasts). In education, blogs can be used as instructional resources. These blogs are referred to as edublogs. Microblogging is another type of blogging, featuring very short posts.

On 16 February 2011, there were over 156 million public blogs in existence.

On 20 February 2014, there were around 172 million Tumblr^[4] and 75.8 million WordPress^[5] blogs in existence worldwide. According to critics and other bloggers, Blogger is the most popular blogging service used today. However, Blogger does not offer public statistics.^[6][7] Technorati lists 1.3 million blogs as of February 22, 2014.^[8]

The term "weblog" was coined by Jorn Barger^[9] on 17 December 1997. The short form, "blog", was coined by Peter Merholz, who jokingly broke the word weblog into the phrase we blog in the sidebar of his blog Peterme.com in April or May 1999.^[10][11][12] Shortly thereafter, Evan Williams at Pyra Labs used "blog" as both a noun and verb ("to blog", meaning "to edit one's weblog or to post to one's weblog") and devised the term "blogger" in connection with Pyra Labs' Blogger product, leading to the popularization of the terms.^[13]

Before blogging became popular, digital communities took many forms including Usenet, commercial online services such as GEnie, Byte Information Exchange (BIX) and the early CompuServe, e-mail lists,^[14] and Bulletin Board Systems (BBS). In the 1990s, Internet forum software created running conversations with "threads". Threads are topical connections between messages on a virtual "corkboard". From 14 June 1993, Mosaic Communications Corporation maintained their "What’s New"^[15] list of new websites, updated daily and archived monthly. The page was accessible by a special "What's New" button in the Mosaic web browser.

The earliest instance of a commercial blog was on the first business to consumer Web site created in 1995 by Ty, Inc., which featured a blog in a section called "Online Diary". The entries were maintained by featured Beanie Babies that were voted for monthly by Web site visitors.^[16]

The modern blog evolved from the online diary where people would keep a running account of the events in their personal lives. Most such writers called themselves diarists, journalists, or journalers. Justin Hall, who began personal blogging in 1994 while a student at Swarthmore College, is generally recognized as one of the earlier bloggers,^[17] as is Jerry Pournelle.^[18] Dave Winer's Scripting News is also credited with being one of the older and longer running weblogs.^[19][20] The Australian Netguide magazine maintained the Daily Net News^[21] on their web site from 1996. Daily Net News ran links and daily reviews of new websites, mostly in Australia.

Another early blog was Wearable Wireless Webcam, an online shared diary of a person's personal life combining text, digital video, and digital pictures transmitted live from a wearable computer and EyeTap device to a web site in 1994. This practice of semi-automated blogging with live video together with text was referred to as sousveillance, and such journals were also used as evidence in legal matters. Some early bloggers, such as The Misanthropic Bitch, who began in 1997, actually referred to their online presence as a zine, before the term blog entered common usage.

Early blogs were simply manually updated components of common Websites. In 1995, the "Online Diary" on the Ty, Inc. Web site was produced and updated manually before any blogging programs were available. Posts were made to appear in reverse chronological order by manually updating text based HTML code using FTP software in real time several times a day. To users, this offered the appearance of a live diary that contained multiple new entries per day. At the beginning of each new day, new diary entries were manually coded into a new HTML file, and the start of each month, diary entries were archived into its own folder which contained a separate HTML page for every day of the month. Then menus that contained links to the most recent diary entry were updated manually throughout the site. This text-based method of organizing thousands of files served as a springboard to define future blogging styles that were captured by blogging software developed years later.^[16]

The evolution of electronic and software tools to facilitate the production and maintenance of Web articles posted in reverse chronological order made the publishing process feasible to a much larger and less technically-inclined population.

Ultimately, this resulted in the distinct class of online publishing that produces blogs we recognize today.

For instance, the use of some sort of browser-based software is now a typical aspect of "blogging".

Blogs can be hosted by dedicated blog hosting services, on regular web hosting services, or run using blog software.

After a slow start, blogging rapidly gained in popularity.

Blog usage spread during 1999 and the years following, being further popularized by the near-simultaneous arrival of the first hosted blog tools:

An early milestone in the rise in importance of blogs came in 2002, when many bloggers focused on comments by U.S. Senate Majority Leader Trent Lott.^[23] Senator Lott, at a party honoring U.S. Senator Strom Thurmond, praised Senator Thurmond by suggesting that the United States would have been better off had Thurmond been elected president. Lott's critics saw these comments as a tacit approval of racial segregation, a policy advocated by Thurmond's 1948 presidential campaign. This view was reinforced by documents and recorded interviews dug up by bloggers. (See Josh Marshall's Talking Points Memo

Similarly, blogs were among the driving forces behind the "Rathergate" scandal. To wit: (television journalist) Dan Rather presented documents (on the CBS show 60 Minutes) that conflicted with accepted accounts of President Bush's military service record. Bloggers declared the documents to be forgeries and presented evidence and arguments in support of that view. Consequently, CBS apologized for what it said were inadequate reporting techniques (see Little Green Footballs). Many bloggers view this scandal as the advent of blogs' acceptance by the mass media, both as a news source and opinion and as means of applying political pressure. The impact of these stories gave greater credibility to blogs as a medium of news dissemination. Though often seen as partisan gossips, bloggers sometimes lead the way in bringing key information to public light, with mainstream media having to follow their lead. More often, however, news blogs tend to react to material already published by the mainstream media. Meanwhile, an increasing number of experts blogged, making blogs a source of in-depth analysis.

In Russia, some political bloggers have started to challenge the dominance of official, overwhelmingly pro-government media. Bloggers such as Rustem Adagamov and Alexei Navalny have many followers and the latter's nickname for the ruling United Russia party as the "party of crooks and thieves" has been adopted by anti-regime protesters.^[24] This led to the Wall Street Journal calling Navalny "the man Vladimir Putin fears most" in March 2012.^[25]

By 2004, the role of blogs became increasingly mainstream, as political consultants, news services, and candidates began using them as tools for outreach and opinion forming. Blogging was established by politicians and political candidates to express opinions on war and other issues and cemented blogs' role as a news source. (See Howard Dean and Wesley Clark.) Even politicians not actively campaigning, such as the UK's Labour Party's MP Tom Watson, began to blog to bond with constituents. In January 2005, Fortune magazine listed eight bloggers whom business people "could not ignore": Peter Rojas, Xeni Jardin, Ben Trott, Mena Trott, Jonathan Schwartz, Jason Goldman, Robert Scoble, and Jason Calacanis.^[26]

Israel was among the first national governments to set up an official blog.^[27] Under David Saranga, the Israeli Ministry of Foreign Affairs became active in adopting Web 2.0 initiatives, including an official video blog^[27] and a political blog.^[27] The Foreign Ministry also held a microblogging press conference via Twitter about its war with Hamas, with Saranga answering questions from the public in common text-messaging abbreviations during a live worldwide press conference.^[29] The questions and answers were later posted on IsraelPolitik, the country's official political blog.^[30]

The impact of blogging upon the mainstream media has also been acknowledged by governments.

In 2009, the presence of the American journalism industry had declined to the point that several newspaper corporations were filing for bankruptcy, resulting in less direct competition between newspapers within the same circulation area.

Discussion emerged as to whether the newspaper industry would benefit from a stimulus package by the federal government.

U.S.

President Barack Obama acknowledged the emerging influence of blogging upon society by saying "if the direction of the news is all blogosphere, all opinions, with no serious fact-checking, no serious attempts to put stories in context, then what you will end up getting is people shouting at each other across the void but not a lot of mutual understanding”.^[31] Between 2009 and 2012, an Orwell Prize for blogging was awarded.

There are many different types of blogs, differing not only in the type of content, but also in the way that content is delivered or written.

As the popularity of blogging continues to rise, the commercialisation of blogging is rapidly increasing.

Many corporations and companies collaborate with bloggers to increase advertising and engage online communities towards their products.

In the book Fans, Bloggers, and Gamers, Henry Jenkins stated that "Bloggers take knowledge in their own hands, enabling successful navigation within and between these emerging knowledge cultures. One can see such behaviour as co-optation into commodity culture insofar as it sometimes collaborates with corporate interests, but one can also see it as increasing the diversity of media culture, providing opportunities for greater inclusiveness, and making more responsive to consumers."^[47]

As of 2008, blogging had become such a mania that a new blog was created every second of every minute of every hour of every day.^[48] Researchers have actively analyzed the dynamics of how blogs become popular. There are essentially two measures of this: popularity through citations, as well as popularity through affiliation (i.e., blogroll). The basic conclusion from studies of the structure of blogs is that while it takes time for a blog to become popular through blogrolls, permalinks can boost popularity more quickly, and are perhaps more indicative of popularity and authority than blogrolls, since they denote that people are actually reading the blog's content and deem it valuable or noteworthy in specific cases.^[49]

The blogdex project was launched by researchers in the MIT Media Lab to crawl the Web and gather data from thousands of blogs in order to investigate their social properties. Information was gathered by the tool for over four years, during which it autonomously tracked the most contagious information spreading in the blog community, ranking it by recency and popularity. It can, therefore, be considered the first instantiation of a memetracker. The project was replaced by tailrank.com which in turn has been replaced by spinn3r.com.

Blogs are given rankings by Alexa Internet (web hits of Alexa Toolbar users), and formerly by blog search engine Technorati based on the number of incoming links (Technorati stopped doing this in 2014). In August 2006, Technorati found that the most linked-to blog on the internet was that of Chinese actress Xu Jinglei.^[50] Chinese media Xinhua reported that this blog received more than 50 million page views, claiming it to be the most popular blog in the world.^[51] Technorati rated Boing Boing to be the most-read group-written blog.^[50]

Many bloggers, particularly those engaged in participatory journalism, are amateur journalists, and thus they differentiate themselves from the professional reporters and editors who work in mainstream media organizations. Other bloggers are media professionals who are publishing online, rather than via a TV station or newspaper, either as an add-on to a traditional media presence (e.g., hosting a radio show or writing a column in a paper newspaper), or as their sole journalistic output. Some institutions and organizations see blogging as a means of "getting around the filter" of media "gatekeepers" and pushing their messages directly to the public. Many mainstream journalists, meanwhile, write their own blogs—well over 300, according to CyberJournalist.net's J-blog list. The first known use of a blog on a news site was in August 1998, when Jonathan Dube of The Charlotte Observer published one chronicling Hurricane Bonnie.^[52]

Some bloggers have moved over to other media.

The following bloggers (and others) have appeared on radio and television: Duncan Black (known widely by his pseudonym, Atrios), Glenn Reynolds (Instapundit), Markos Moulitsas Zúniga (Daily Kos), Alex Steffen (Worldchanging), Ana Marie Cox (Wonkette), Nate Silver (FiveThirtyEight.com), and Ezra Klein (Ezra Klein blog in The American Prospect, now in the Washington Post). In counterpoint, Hugh Hewitt exemplifies a mass media personality who has moved in the other direction, adding to his reach in "old media" by being an influential blogger. Similarly, it was Emergency Preparedness and Safety Tips On Air and Online blog articles that captured Surgeon General of the United States Richard Carmona's attention and earned his kudos for the associated broadcasts by talk show host Lisa Tolliver and Westchester Emergency Volunteer Reserves-Medical Reserve Corps Director Marianne Partridge.^[53][54]

Blogs have also had an influence on minority languages, bringing together scattered speakers and learners; this is particularly so with blogs in Gaelic languages. Minority language publishing (which may lack economic feasibility) can find its audience through inexpensive blogging. There are examples of bloggers who have published books based on their blogs, e.g., Salam Pax, Ellen Simonetti, Jessica Cutler, ScrappleFace. Blog-based books have been given the name blook. A prize for the best blog-based book was initiated in 2005,^[55] the Lulu Blooker Prize.^[56] However, success has been elusive offline, with many of these books not selling as well as their blogs. The book based on Julie Powell's blog "The Julie/Julia Project" was made into the film Julie & Julia

Consumer-generated advertising is a relatively new and controversial development, and it has created a new model of marketing communication from businesses to consumers. Among the various forms of advertising on blog, the most controversial are the sponsored posts.^[57] These are blog entries or posts and may be in the form of feedback, reviews, opinion, videos, etc. and usually contain a link back to the desired site using a keyword or several keywords. Blogs have led to some disintermediation and a breakdown of the traditional advertising model, where companies can skip over the advertising agencies (previously the only interface with the customer) and contact the customers directly via social media websites. On the other hand, new companies specialised in blog advertising have been established, to take advantage of this new development as well. However, there are many people who look negatively on this new development. Some believe that any form of commercial activity on blogs will destroy the blogosphere’s credibility.^[58]

Blogging can result in a range of legal liabilities and other unforeseen consequences.^[59]

Several cases have been brought before the national courts against bloggers concerning issues of defamation or liability. U.S. payouts related to blogging totaled $17.4 million by 2009; in some cases these have been covered by umbrella insurance.^[60] The courts have returned with mixed verdicts. Internet Service Providers (ISPs), in general, are immune from liability for information that originates with third parties (U.S. Communications Decency Act and the EU Directive 2000/31/EC). In Doe v. Cahill, the Delaware Supreme Court held that stringent standards had to be met to unmask the anonymous bloggers, and also took the unusual step of dismissing the libel case itself (as unfounded under American libel law) rather than referring it back to the trial court for reconsideration.^[61] In a bizarre twist, the Cahills were able to obtain the identity of John Doe, who turned out to be the person they suspected: the town's mayor, Councilman Cahill's political rival. The Cahills amended their original complaint, and the mayor settled the case rather than going to trial.

In January 2007, two prominent Malaysian political bloggers, Jeff Ooi and Ahirudin Attan, were sued by a pro-government newspaper, The New Straits Times Press (Malaysia) Berhad, Kalimullah bin Masheerul Hassan, Hishamuddin bin Aun and Brenden John a/l John Pereira over an alleged defamation. The plaintiff was supported by the Malaysian government.^[62] Following the suit, the Malaysian government proposed to "register" all bloggers in Malaysia in order to better control parties against their interest.^[63] This is the first such legal case against bloggers in the country. In the United States, blogger Aaron Wall was sued by Traffic Power for defamation and publication of trade secrets in 2005.^[64] According to Wired magazine, Traffic Power had been "banned from Google for allegedly rigging search engine results."^[65] Wall and other "white hat" search engine optimization consultants had exposed Traffic Power in what they claim was an effort to protect the public. The case was dismissed for lack of personal jurisdiction, and Traffic Power failed to appeal within the allowed time.^[66]

In 2009, NDTV issued a legal notice to Indian blogger Kunte for a blog post criticizing their coverage of the Mumbai attacks. The blogger unconditionally withdrew his post, which resulted in several Indian bloggers criticizing NDTV for trying to silence critics.^[68]

Employees who blog about elements of their place of employment can begin to affect the reputation of their employer, either in a positive way, if the employee is praising the employer and its workplaces, or in a negative way, if the blogger is making negative comments about the company or its practices.

In general, attempts by employee bloggers to protect themselves by maintaining anonymity have proved ineffective.^[69] In 2009, a controversial and landmark decision by The Hon. Mr Justice Eady refused to grant an order to protect the anonymity of Richard Horton. Horton was a police officer in the United Kingdom who blogged about his job under the name "NightJack".^[70]

Delta Air Lines fired flight attendant Ellen Simonetti because she posted photographs of herself in uniform on an airplane and because of comments posted on her blog "Queen of Sky: Diary of a Flight Attendant" which the employer deemed inappropriate.^[71][72] This case highlighted the issue of personal blogging and freedom of expression versus employer rights and responsibilities, and so it received wide media attention. Simonetti took legal action against the airline for "wrongful termination, defamation of character and lost future wages".^[73] The suit was postponed while Delta was in bankruptcy proceedings.^[74]

In early 2006, Erik Ringmar, a senior lecturer at the London School of Economics, was ordered by the convenor of his department to "take down and destroy" his blog in which he discussed the quality of education at the school.^[75]

Mark Jen was terminated in 2005 after 10 days of employment as an assistant product manager at Google for discussing corporate secrets on his personal blog, then called 99zeros and hosted on the Google-owned Blogger service.^[76] He blogged about unreleased products and company finances a week before the company's earnings announcement. He was fired two days after he complied with his employer's request to remove the sensitive material from his blog.^[77]

In India, blogger Gaurav Sabnis resigned from IBM after his posts questioned the claims made by a management school.^[78] Jessica Cutler, aka "The Washingtonienne", blogged about her sex life while employed as a congressional assistant. After the blog was discovered and she was fired,^[79] she wrote a novel based on her experiences and blog: The Washingtonienne: A Novel. As of 2006, Cutler is being sued by one of her former lovers in a case that could establish the extent to which bloggers are obligated to protect the privacy of their real life associates.^[80]

Catherine Sanderson, a.k.a. Petite Anglaise, lost her job in Paris at a British accountancy firm because of blogging.^[81] Although given in the blog in a fairly anonymous manner, some of the descriptions of the firm and some of its people were less than flattering. Sanderson later won a compensation claim case against the British firm, however.^[82]

On the other hand, Penelope Trunk wrote an upbeat article in the Boston Globe in 2006, entitled "Blogs 'essential' to a good career".^[83] She was one of the first journalists to point out that a large portion of bloggers are professionals and that a well-written blog can help attract employers.

Business owners who blog about their business can also run into legal consequences.

Mark Cuban, owner of the Dallas Mavericks, was fined during the 2006 NBA playoffs for criticizing NBA officials on the court and in his blog.^[84]

Blogging can sometimes have unforeseen consequences in politically sensitive areas.

In some countries, Internet police or secret police may monitor blogs and arrest blog authors of commentators. Blogs can be much harder to control than broadcast or print media, because a person can create a blog whose authorship is hard to trace, by using anonymity technology such as Tor. As a result, totalitarian and authoritarian regimes often seek to suppress blogs and/or to punish those who maintain them.

In Singapore, two ethnic Chinese individuals were imprisoned under the country’s anti-sedition law for posting anti-Muslim remarks in their blogs.^[85] Egyptian blogger Kareem Amer was charged with insulting the Egyptian president Hosni Mubarak and an Islamic institution through his blog. It is the first time in the history of Egypt that a blogger was prosecuted. After a brief trial session that took place in Alexandria, the blogger was found guilty and sentenced to prison terms of three years for insulting Islam and inciting sedition, and one year for insulting Mubarak.^[86] Egyptian blogger Abdel Monem Mahmoud was arrested in April 2007 for anti-government writings in his blog. Monem is a member of the then banned Muslim Brotherhood. After the 2011 Egyptian revolution, the Egyptian blogger Maikel Nabil Sanad was charged with insulting the military for an article he wrote on his personal blog and sentenced to 3 years.^[87]

After expressing opinions in his personal blog about the state of the Sudanese armed forces, Jan Pronk, United Nations Special Representative for the Sudan, was given three days notice to leave Sudan. The Sudanese army had demanded his deportation.^[88][89] In Myanmar, Nay Phone Latt, a blogger, was sentenced to 20 years in jail for posting a cartoon critical of head of state Than Shwe.^[90]

One consequence of blogging is the possibility of online or in-person attacks or threats against the blogger, sometimes without apparent reason.

In some cases, bloggers have faced cyberbullying. Kathy Sierra, author of the blog "Creating Passionate Users",^[91] was the target of threats and misogynistic insults to the point that she canceled her keynote speech at a technology conference in San Diego, fearing for her safety.^[92] While a blogger's anonymity is often tenuous, Internet trolls who would attack a blogger with threats or insults can be emboldened by the anonymity of the online environment, where some users are known only by a pseudonymous "username" (e.g., "Hacker1984"). Sierra and supporters initiated an online discussion aimed at countering abusive online behavior^[93] and developed a Blogger's Code of Conduct, which set out a rules for behaviour in the online space.

The Blogger's Code of Conduct is a proposal by Tim O'Reilly for bloggers to enforce civility on their blogs by being civil themselves and moderating comments on their blog. The code was proposed in 2007 due to threats made to blogger Kathy Sierra.^[94] The idea of the code was first reported by BBC News, who quoted O'Reilly saying, "I do think we need some code of conduct around what is acceptable behaviour, I would hope that it doesn't come through any kind of regulation it would come through self-regulation."^[95]

O'Reilly and others came up with a list of seven proposed ideas:^[96][97][98]

These ideas were predictably intensely discussed on the Web and in the media.

While the internet has continued to grow, with online activity and discourse only picking up both in positive and negative ways in terms of blog interaction, the proposed Code has drawn more widespread attention to the necessity of monitoring blogging activity and social norms being as important online as offline.