vi filenamewill put filename into a buffer, and display the file on the screen. If the file is larger than the screen can display, the screen will act as a window into the file. At the beginning of the session, the screen will display the first part of the file.
If filename does not exist, vi will create it.
Upon entry to vi, the bottom of the screen will print the name of the file being edited, the number of lines in the file, and the size of the file (in characters).