Application software (app for short) is software designed to perform a group of coordinated functions, tasks, or activities for the benefit of the user. Examples of an application include a word processor, a spreadsheet, an accounting application, a web browser, an email client, a media player, a file viewer, an aeronautical flight simulator, a console game or a photo editor. The collective noun application software refers to all applications collectively. This contrasts with system software, which is mainly involved with running the computer.
In information technology, an application (app), application program or software application is a computer program designed to help people perform an activity. An application thus differs from an operating system (which runs a computer), a utility (which performs maintenance or general-purpose chores), and a programming tool (with which computer programs are created). Depending on the activity for which it was designed, an application can manipulate text, numbers, audio, graphics and a combination of these elements. Some application packages focus on a single task, such as word processing; others, called integrated software include several applications.
User-written software tailors systems to meet the user's specific needs. User-written software includes spreadsheet templates, word processor macros, scientific simulations, audio, graphics, and animation scripts. Even email filters are a kind of user software. Users create this software themselves and often overlook how important it is.
The delineation between system software such as operating systems and application software is not exact, however, and is occasionally the object of controversy. For example, one of the key questions in the United States v. Microsoft Corp. antitrust trial was whether Microsoft's Internet Explorer web browser was part of its Windows operating system or a separable piece of application software. As another example, the GNU/Linux naming controversy is, in part, due to disagreement about the relationship between the Linux kernel and the operating systems built over this kernel. In some types of embedded systems, the application software and the operating system software may be indistinguishable to the user, as in the case of software used to control a VCR, DVD player or microwave oven. The above definitions may exclude some applications that may exist on some computers in large organizations. For an alternative definition of an app: see Application Portfolio Management.
The word "application", once used as an adjective, is not restricted to the "of or pertaining to application software" meaning. For example, concepts such as application programming interface (API), application server, application virtualization, application lifecycle management and portable application apply to all computer programs alike, not just application software.
Apps and killer apps
Some applications are available in versions for several different platforms; others only work on one and are thus called, for example, a Geography application for Microsoft Windows, or an Android application for education, or a Linux game. Sometimes a new and popular application arises which only runs on one platform, increasing the desirability of that platform. This is called a killer application or killer app. For example, VisiCalc was the first modern spreadsheet software for the Apple II and helped selling the then-new personal computers into offices. For Blackberry it was their email software.
In recent years, the shortened term "app" (coined in 1981 or earlier) has become popular to refer to applications for mobile devices such as smartphones and tablets, the shortened form matching their typically smaller scope compared to applications on PCs. Even more recently, the shortened version is used for desktop application software as well.
There are many different and alternative ways in order to classify application software.
By the legal point of view, application software is mainly classified with a black box approach, in relation to the rights of its final end-users or subscribers (with eventual intermediate and tiered subscription levels).
Software applications are also classified in respect of the programming language in which the source code is written or executed, and respect of their purpose and outputs.
By property and use rights
Proprietary software is placed under the exclusive copyright, and a software license grants limited usage rights. The open-closed principle states that software may be "open only for extension, but not for modification". Such applications can only get add-on by third-parties.
Free and open-source software shall be run, distributed, sold or extended for any purpose, and -being open- shall be modified or reversed in the same way.
Public-domain software is a type of FOSS, which is royalty-free and - openly or reservedly- can be run, distributed, modified, reversed, republished or created in derivative works without any copyright attribution and therefore revocation. It can even be sold, but without transferring the public domain property to other single subjects. Public-domain SW can be released under an (un)licens ing legal statement, which enforces those terms and conditions for an indefinite duration (for a lifetime, or forever).
By coding language
By purpose and output
LibreOffice Writer, an open-source word processor that is a component of LibreOffice (running on Linux Mint)
Application software can also be seen as being either horizontal or vertical. Horizontal applications are more popular and widespread, because they are general purpose, for example word processors or databases. Vertical applications are niche products, designed for a particular type of industry or business, or department within an organization. Integrated suites of software will try to handle every specific aspect possible of, for example, manufacturing or banking worker, or accounting, or customer service.
An application suite consists of multiple applications bundled together. They usually have related functions, features and user interfaces, and may be able to interact with each other, e.g. open each other's files. Business applications often come in suites, e.g. Microsoft Office, LibreOffice and iWork, which bundle together a word processor, a spreadsheet, etc.; but suites exist for other purposes, e.g. graphics or music.
Enterprise software addresses the needs of an entire organization's processes and data flows, across several departments, often in a large distributed environment. Examples include enterprise resource planning systems, customer relationship management (CRM) systems and supply chain management software. Departmental Software is a sub-type of enterprise software with a focus on smaller organizations or groups within a large organization. (Examples include travel expense management and IT Helpdesk.)
Enterprise infrastructure software provides common capabilities needed to support enterprise software systems. (Examples include databases, email servers, and systems for managing networks and security.)
Information worker software lets users create and manage information, often for individual projects within a department, in contrast to enterprise management. Examples include time management, resource management, analytical, collaborative and documentation tools. Word processors, spreadsheets, email and blog clients, personal information system, and individual media editors may aid in multiple information worker tasks.
Content access software is used primarily to access content without editing, but may include software that allows for content editing. Such software addresses the needs of individuals and groups to consume digital entertainment and published digital content. (Examples include media players, web browsers, and help browsers.)
Educational software is related to content access software, but has the content or features adapted for use in by educators or students. For example, it may deliver evaluations (tests), track progress through material, or include collaborative capabilities.
Simulation software simulates physical or abstract systems for either research, training or entertainment purposes.
Media development software generates print and electronic media for others to consume, most often in a commercial or educational setting. This includes graphic-art software, desktop publishing software, multimedia development software, HTML editors, digital-animation editors, digital audio and video composition, and many others.
Product engineering software is used in developing hardware and software products. This includes computer-aided design (CAD), computer-aided engineering (CAE), computer language editing and compiling tools, integrated development environments, and application programmer interfaces.
Entertainment Software can refer to video games, screen savers, programs to display motion pictures or play recorded music, and other forms of entertainment which can be experienced through use of a computing device.
The operating system itself can be considered application software when performing simple calculating, measuring, rendering, and word processing tasks not used to control hardware via command-line interface or graphical user interface. This does not include application software bundled within operating systems such as a software calculator or text editor.
Information worker software
Data management Contact manager Spreadsheet Database software
Documentation Document automation Word processor Desktop publishing software Diagramming software Presentation software Email Blog software
Financial software Day trading software Banking software Clearing systems Arithmetic software
Field service management Workforce management software
Project management software Calendaring software Employee scheduling software Workflow software
Sales readiness software
Enterprise infrastructure software
Business workflow software
Database management system (DBMS)
Digital asset management (DAM) software
Document management software
Geographic information system (GIS)
Computer simulators Scientific simulators Social simulators Battlefield simulators Emergency simulators Vehicle simulators Flight simulators Driving simulators Simulation games Vehicle simulation games
Media development software
3D computer graphics software
Graphic art software Raster graphics editor Vector graphics editor
Video editing software
Audio editing software Digital audio workstation
Music sequencer Scorewriter
Game development tool