The two basic modes involve either editing text and managing the file,
and actually inputting data.

The COMMAND mode is where you move the cursor around in the file, search
for text strings, replace text, save your work, delete lines and so on.

The INPUT/APPEND mode (some will say there are three modes, separating
the input and append modes. When in this mode you are actually typing
the text into the file.

The vi editor was developed before 101 keyboards were created. In order for
the typist to move the cursor in a "visual" mode, the key sequences were created.
It is interesting to note, for those of us that remember, or care,
that Word Star, the first PC based word processing program to gain popularity,
used a similar approach.

Learning the basic cursor movement of the vi editor will allow you to navigate
easily in the command line history of the Bourne, Korn and Posix shell!