To find a program or file, you normally have to open a Finder window and then look for the program or file that you want to use. This means going through several steps just to start a program. If you use a program or file often, going through multiple steps can be annoying.
OS X offers the Dock as a place to store commonly used programs, files, and folders so that you can access them with one click. The Dock doesn’t have room to store everything on your computer, just the programs, files, and folders that you use most often.
Think of the Dock as a shortcut to your favorite programs, ...
