The <DEL> or <Delete> key makes the first character AFTER the cursor
disappear, and everything after it then moves back one space to close up
the hole.
Example:
If I have this in my document ... Most trees are green.
And my cursor is after the 'a', like this: Most trees a|re green.
Now, if I hit the <delete> key, it deletes the
'r' after the cursor, and the hole closes up,
and the cursor stays where it is: Most trees a|e green.