What Programmer is
A person who designs, codes, tests and documents a computer program or Web site. Professional programmers often hold college degrees in computer science, but a great deal of programming is done by individuals who are self-taught, with little or no formal training.
The meaning of Application
Used interchangeably with program and software, this is a general term for a program that performs specific tasks, such as word processing, database management, e-mail sending or retrieval, or Web browsing. Unlike system software, which maintains and organizes the computer system (such as the operating system), an app is an end-user program.