Description: It is a button on the keyboard next to the 'a'.
Use: If pressed, it makes every letter that you type into all caps. Some people on the internet use it to emphasize a person's statement.
Caps Lock is th button on the keyboeard above it is the tab. The one below it is shift.
TOMMY THAT'S NOT NICE! That sentence would universally be translated as yelling, even without the exclamation point at the end.