There are two ways of removing text: deletion, after which the deleted text is not recoverable (except with the Undo command); and killing, which appends the deleted text to a kill ring, so that it may be recovered using the Un-Kill and Rotate Kill Ring commands. The first section contains details of commands to delete text, and the second details of commands to kill text.
The use of prefix arguments with this set of commands can be very useful. In general, using a negative prefix argument repeats these commands a certain number of times in the opposite logical direction. For example, the key sequence Ctrl+U 10 +D deletes 10 words after the current point, but the key sequence Ctrl+U -10 +D deletes 10 words before the current point.