The Ctrl key on your computer to the meaning of control.
This is the key to the key combination, say, i.e., it must be along with the arrow keys) go up for us to do. In various software have defined that the role of this key with other Keys, what. For example it is possible in a software combination of this key with the S KEY makes the Save (Save), or combine this key with O, causing the opening (Open) the window.