How does a switch differ from a hub?

A.
A switch does not induce any latency into the frame transfer time.

B.
A switch tracks MAC addresses of directly-connected devices.

C.
A switch operates at a lower, more efficient layer of the OSI model.

D.
A switch decreases the number of broadcast domains.

E.
A switch decreases the number of collision domains.

Explanation:
Some of the features and functions of a switch include:
A switch is essentially a fast, multi-port bridge, which can contain dozens of ports.
Rather than creating two collision domains, each port creates its own collision domain.
In a network of twenty nodes, twenty collision domains exist if each node is plugged into its
own switch port.
If an uplink port is included, one switch creates twenty-one single-node collision domains.
A switch dynamically builds and maintains a Content-Addressable Memory (CAM) table,
holding all of the necessary MAC information for each port.
For a detailed description of how switches operate, and their key differences to hubs, see the
reference link below.
ReferencE. http://www.cisco.com/warp/public/473/lan-switch-cisco.shtml