How Keyboard Keys Works

Keyboards use either one of two common technologies. One is the keys make contact with foil which is called a foil contact. The other is when the keys make a metal contact. On a foil contact keyboard when you press the key two pieces of foil make contact and close a circuit. After you press a key, a small spring just under the keycap raises the key again.

More expensive and heavier metal contact keyboards provide a different feel and touch to the fingers than the foil contact keyboards. Although these keyboards are made by various companies, their mainly produced by AT&T and IBM.  Most users can notice the sturdy construction that give the keystroke a clear definitive contact. Metal contact keyboards also use a spring right under the keycap to raise the key.