Computer Networks

- ARPANET: Advanced Research Projects Agency Network
- MAC: Media Access Control
- ISP: Internet Service Provider
- URI: Uniform Resource Identifier

A network is a group of two or more similar things or people interconnected with each other. In computer terms, a computer network is an interconnection among two or more computers or computing devices that allows them to share data and resources.

Any two advantages are:
- It allows computers to share data among each other.
- It allows sharing of resources, such as a printer or storage, among multiple computers.

Other valid advantage from the chapter: it helps in simultaneous communication with many parties through email, websites, audio/video calls, etc.

LAN and WAN differ as follows:

- LAN (Local Area Network) covers a limited geographical area such as a single room, office, building, school, college, or campus. It has high data transfer speed and is generally more secure.
- WAN (Wide Area Network) covers a very large geographical area such as different cities, countries, or continents. It connects LANs and MANs spread over large distances. The Internet is the largest WAN.

So, LAN is small and local, while WAN is large and wide-spread.

Some commonly used networking devices are modem, hub, switch, repeater, router, gateway, and Ethernet card/NIC.

Two universities in different states are spread across different geographical locations, so they need a Wide Area Network (WAN). A WAN connects computers and networks across different cities, states, countries, or continents.

The arrangement of computers and other peripherals in a network is called its topology.

The popular network topologies are:
- Mesh topology
- Ring topology
- Bus topology
- Star topology
- Tree or Hybrid topology

Tree topology is a hierarchical topology in which there are multiple branches, and each branch can have one or more basic topologies like star, ring, or bus.

Bus topology has a single backbone wire called the bus, which is shared among all nodes.

So, the main difference is that tree topology has a branched hierarchical structure, while bus topology uses one common backbone wire shared by all nodes.