What is Taskbar icon in computer

There is a bar just below the desktop which is called Taskbar. When a program is run, its icon is visible to us in the taskbar, and even after minimizing the program, the program's icon remains in the taskbar. Apart from this, the icons of some selected programs can be pinned to the taskbar so that the program can be run directly from the taskbar even after the window of other program is open.