Understanding Net-Speak

INTERNET
The Net is a global mesh of computer networks sharing a common software standard called TCP/IP. Its backbones are high-speed fiber trunk-lines owned by telephone companies. National service providers such as UUNET aggregate data traffic and zip it over the backbones. They work with local service providers who connect to customers via PC modems or digital links.

INTRANET
Many companies have built internal networks using the same software standards as the Internet. Companies use intranets to distribute information and speed data among offices. Intranet activities usually take place behind secure ''firewalls'' so that only authorized users have access. An intranet can span multiple business locations via the Internet.

EXTRANET
When a company throws open its internal network--or intranet--to selected business partners, the intranet becomes an ''extranet.'' Suppliers, distributors, and other authorized users can now connect to the company's network over the Net or through virtual private networks. Once inside, they can view data the company makes available.