Lesson Four TEXT Important PC Keys ENTER or RETURN Usually placed where
 the carriage-return key would be on an electric typewriter. Sometimes 
the ENTER key is marked with an arrow pointing down and the left. In th
is book we will always speak of the ENTER key, but if you have a keyboa
rd with a key labeled RETURN, it does exactly the same thing as a key l
abeled ENTER. SHIFT Located at the lower left and lower rights of alpha
numeric part of the keyboard. This key works by pressing it together wi
th other keys: usually, the action is to capitalize a letter, but somet
imes there may effects. If you are not a practiced typist, you should u
se this key by pushing it down first, then pressing the other key with 
which it must work. The release both key. If try to push the keys exact
ly together, you will probably fail, and may not get what want. By itse
lf, the SHIFT key normally does nothing whatever. CAPS LOCK Usually loc
ated at the left of the alphanumeric part of the ke4yboard, except om I
BM computers, where it may be at lower rights corner of the alphanumeri
c portion. This key is not like the 'shoft-lock' key on a typewriter; i
ts action applies only to the alphabetic keys. Numerals and punctuation
 keys are not affected by CAPS LOCK. CONTROL (probably marked CTRL) Usu
ally placed on the left wide of the alphanumeric (main) part of the key
board. This key functions like a typewriter's shift key-you push it and
 hold it down while you press another key. This key is typically marked
 'ctrl' or something similar. ALT Usually placed near the lower left si
de of the alphanumeric (main) part of the keyboard. This key is like th
e CONTROL and SHIFT keys-it works in combination with other keys; yoju 
depress and hold down ALT while typing the other key. ESCAPE (probably 
marked Esc) Usually at the top left of the alphanumeric portion. This k
ey is usually pressed by itself. It often has function of interrupting 
or stopping a program. Some times it will cause a process to stop and t
he previous one to resume. BACKSPACE Usually at the top right of the al
phanumeric portion. This key usually erases characters to the left of t
he cursor. It is not the same as the LEFT arrow key, located on the num
eric/cursor keypad, although both keys are often marked with an arrow p
ointing to the left. NUM LOCK Located at the top of the numeric keypad.
 This key is toggle (on-off) switch change the action of the numeric ke
ypad keys from cursor to numbers, and back again. SCROLL LOCK/BREAK Loc
ated at the top of the numeric keypad (on most machines). On IBM keyboa
rds, this key may say SCROLL LOCK on this top, with BREAK written on th
e face of the key. BREAK is, normally say, meant to be used in combinat
ion with the CONTROL key; pressing CONTROL+BREAK will usually halt a pr
ogram or command. Cursor movement keys are marked on the numeric keypad
. When the keypad is in cursor mode (set by NUM LOCK), the arrow keys a
nd other keys function to move the cursor around the CRT screen. INS an
d DEL These keys insert and delete (respectively) characters at the cur
sor position. This are heavily used in application like word processing
. Function keys Usually located either at the extreme left of the keybo
ard or across the top. These keys are under the control of applications
 programs, so they can havge different functions from program to progra
m or even inside a program; to know what they do you must read the manu
al for the program which you are using. The function keys can be used i
n combination with ALT, WHIFT, and CONTROL. F1 This function key is loc
ated on the extreme left of the keyboard or, on some make change to the
 end of it ,this key almost NEVER works the same way inside an applicat
ion program. F3 will retype the entire last command given, let you edit
 it (using BACKSPACE, etc), then press ENTER.