With vi you can use the cursor control keys to indicate to the editor the position within the text at which you wish to make some change such as insert, delete, etc. If the file filename exists, it is loaded into an edit buffer, or if not existing, the new file filename is created and you receive a message. In the case of an existing file, vi displays the first screenfull. When invoked initially, vi is in the command mode, but there is no command prompt for vi. For vi you must have VT100 terminal emulation selected for your communications software.
Commands are case sensitive.