hard drive
Definition:
The device that stores all of a computer's information, even after the computer is turned off. Think of a hard drive as a giant file cabinet for your computer.
Here's a word you may not know...
social network
A social network represents a web site where people gather virtually. Generally, each person that belongs to a social network has his or her own profile page and then becomes "friends" with other members of the social networking site. Friends on the site write blog posts, add their favorite pictures, music and video, as well as write comments on other people's profile pages.
Some of the more popular social networking sites include MySpace, Facebook and Flickr.