At this point you can see that vi has a great deal of functionality. It has commands to change, delete, move (actually delete and put) and to copy (yank). These commands can take numeric arguments, and can effect text to the ``right'' and ``left'' of the cursor. Or they can extend to the beginning or end of the current line. You can ``join'' lines by removing the end of line from one line.
Vi also has many properties which can be ``set'', such as having lines numbered, ignoring case, a margin for automatically wrapping lines, etc. Lets just finish by saying that vi is a capable editor, and that to learn more about this editor you should consult a manual on it. At one time, UNIX World magazine produced posters which listed the capabilities of vi. These may still be available.