An Application, also known as an Application Program or Application Software, is a computer software package that performs a specific function directly for an end user or, in some cases, for another Application. An Application can be self-contained or a group of programs. The program is a set of operations that runs the application for the user.
Some common Application examples include:
Applications use the computer's Operating System (OS) and other supporting programs, typically system software, to function. An Application requests services from and communicates with other technologies via an Application Programming Interface (API).
Source: https://searchsoftwarequality.techtarget.com/definition/application