The most basic delete commands are C-d (
delete-backward-char). C-d deletes the
character after point, the one the cursor is "on top of". This
doesn't move point. DEL deletes the character before the cursor,
and moves point back. You can delete newlines like any other characters
in the buffer; deleting a newline joins two lines. Actually, C-d
and DEL aren't always delete commands; when given arguments, they
kill instead, since they can erase more than one character this way.
The other delete commands are those which delete only whitespace
characters: spaces, tabs and newlines. M-\
delete-horizontal-space) deletes all the spaces and tab
characters before and after point. M-SPC
just-one-space) does likewise but leaves a single space after
point, regardless of the number of spaces that existed previously (even
C-x C-o (
delete-blank-lines) deletes all blank lines
after the current line. If the current line is blank, it deletes all
blank lines preceding the current line as well (leaving one blank line,
the current line).
delete-indentation) joins the current line and the
previous line, by deleting a newline and all surrounding spaces, usually
leaving a single space. See section Indentation.