SWITCHES

Switches are a special type of hub that offers an additional layer of intelligence to basic,
physical-layer repeater hubs. A switch must be able to read the MAC address of each
frame it receives. This information allows switches to repeat incoming data frames only
to the computer or computers to which a frame is addressed. This speeds up the
network and reduces congestion.
Switches operate at both the physical layer and the data link layer of the OSI
Model.