It is profession about application development platform..An application program (application or app for short) is a computer program designed to carry out a specific task other than one relating to the operation of the computer itself,[1] typically to be used by end-users.[2] Word processors, media players, and accounting software are examples. The collective noun refers to all applications collectively.[3] The other principal classifications of software are system software, relating to the operation of the computer, and utility software ("utilities"). Applications may be bundled with the computer and its system software or published separately and may be coded as proprietary, open-source, or projects.[4] The term "app" often refers to applications for mobile devices such as phones. Terminology Edit In information technology, an application (app), application program or application software is a computer program designed to help people perform an activity. 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.[5] 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. Plug-in (computing)- In computing, a plug-in (or plugin, add-in, addin, add-on, or addon) is a software component that adds a specific feature to an existing computer program. When a program supports plug-ins, it enables customization.[1] Mozilla Firefox displaying a list of installed plug-ins Look up plug-in or add-on in Wiktionary, the free dictionary. A theme or skin is a preset package containing additional or changed graphical appearance details, achieved by the use of a graphical user interface (GUI) that can be applied to specific software and websites to suit the purpose, topic, or tastes of different users to customize the look and feel of a piece of computer software or an operating system front-end GUI (and window managers).