EMACS commands are either escape sequences or control sequences.
To enter an escape sequence, press and release the <ESC> key,
then enter the character that represents the command. An escape
sequence to convert a word to uppercase would be:
<ESC>u
Control sequences are issued by pressing and holding the control key,
then entering a character command. A control sequence to delete a
character under the cursor is:
<ctrl-d>
A command can be executed a number of times in succession
by specifying a repeat count. As an example, to delete 10 characters
in a document, issue the following command:
<ctrl-u> 10 <ctrl-d>
The '<ctrl-u> <num>' specifies the number of times the following command is to be repeated.