C-w

Kill the region (kill-region).

M-w

Copy the region into the kill ring (kill-ring-save).

M-d

Kill the next word (kill-word). Words.

M-DEL

Kill one word backwards (backward-kill-word).

C-x DEL

Kill back to beginning of sentence (backward-kill-sentence). Sentences.

M-k

Kill to the end of the sentence (kill-sentence).

C-M-k

Kill the following balanced expression (kill-sexp). Expressions.

M-z char

Kill through the next occurrence of char (zap-to-char).

M-x zap-up-to-char char

Kill up to, but not including, the next occurrence of char.

One of the commonly-used kill commands is C-w (kill-region), which kills the text in the region (Mark). Similarly, M-w (kill-ring-save) copies the text in the region into the kill ring without removing it from the buffer. If the mark is inactive when you type C-w or M-w, the command acts on the text between point and where you last set the mark (Using Region). Emacs also provides commands to kill specific syntactic units: words, with M-=DEL= and M-d (Words); balanced expressions, with C-M-k (Expressions); and sentences, with C-x =DEL= and M-k (Sentences). The command M-z (zap-to-char) combines killing with searching: it reads a character and kills from point up to (and including) the next occurrence of that character in the buffer. A numeric argument acts as a repeat count; a negative argument means to search backward and kill text before point. A history of previously used characters is maintained and can be accessed via the M-p=/=M-n keystrokes. This is mainly useful if the character to be used has to be entered via a complicated input method. A similar command zap-up-to-char kills from point up to, but not including the next occurrence of a character, with numeric argument acting as a repeat count.