address: A number that is assigned to a computer so that messages can be routed to the computer.
hop: A single physical network connection. A packet on the Internet will typically make several “hops” to get from its source computer to its destination.
LAN: Local Area Network. A network covering an area that is limited by the ability for an organization to run wires or the power of a radio transmitter.
leased line: An “always up” connection that an organization leased from a telephone company or other utility to send data across longer distances.
operator (telephone): A person who works for a telephone company and helps people make telephone calls.
packet: A limited-size fragment of a large message. Large messages or files are split into many packets and sent across the Internet. The typical maximum packet size is between 1000 and 3000 characters.
router: A specialized computer that is designed to receive incoming packets on many links and quickly forward the packets on the best outbound link to speed the packet to its destination.
store-and-forward network: A network where data is sent from one computer to another with the message being stored for relatively long periods of time in an intermediate computer waiting for an outbound network connection to become available.
WAN: Wide Area Network. A network that covers longer distances, up to sending data completely around the world. A WAN is generally constructed using communication links owned and managed by a number of different organizations.