Answer :

Well, unless you press it with another key (such as control etc) it will do the same function as the return key. It'll only delete a space or a letter...number...unicorn ~
AL2006

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.