Architecture
See also: Software architecture
People who use modern general purpose computers (as opposed to embedded systems, analog computers and supercomputers) usually see three layers of software performing a variety of tasks: platform, application, and user software.[citation needed]
- Platform software: The platform includes the firmware, device drivers, an operating system, and typically a graphical user interface which, in total, allow a user to interact with the computer and its peripherals (associated equipment). Platform software often comes bundled with the computer. On a PC one will usually have the ability to change the platform software.
- Application software: Application software is what most people think of when they think of software.[citation needed] Typical examples include office suites and video games. Application software is often purchased separately from computer hardware. Sometimes applications are bundled with the computer, but that does not change the fact that they run as independent applications. Applications are usually independent programs from the operating system, though they are often tailored for specific platforms. Most users think of compilers, databases, and other “system software” as applications.[citation needed]
- User-written software: End-user development tailors systems to meet users’ specific needs. User software includes spreadsheet templates and word processor templates.[citation needed] Even email filters are a kind of user software. Users create this software themselves and often overlook how important it is.[citation needed] Depending on how competently the user-written software has been integrated into default application packages, many users may not be aware of the distinction between the original packages, and what has been added by co-workers.[citation needed]
Execution
