A network is a group of connected computers that can share data and resources.
LAN vs WAN
- LAN (Local Area Network): Covers a small geographical area, like a home or office. You usually own the network hardware.
- WAN (Wide Area Network): Covers a large geographical area, like a country or the world. The Internet is the largest WAN. You usually rent communication lines from a third party.
Network Hardware & Topologies
Network devices include:
- NIC (Network Interface Card): Allows a device to connect to a network.
- Switches: Connects devices within a LAN.
- Routers: Connects multiple networks and directs data traffic.
- WAPs (Wireless Access Points): Allows wireless devices to connect to a network.
A topology is the layout of the network. Two common types are:
- Star Topology: All devices connect to a central switch. If one device fails, others remain unaffected.
- Mesh Topology: Every device connects to every other device. Very reliable but expensive to set up.
Protocols & Layers
A protocol is a set of rules for communication. The Internet uses the TCP/IP protocol suite. Other common protocols include:
- HTTP(S): For web pages.
- FTP: For file transfers.
- POP, IMAP, SMTP: For email.
The network layers model breaks down data transmission into smaller layers, making the system more flexible.
The Internet & IP Addressing
The Internet is a global network of interconnected networks. The cloud refers to services (like storage and apps) accessed online. Your device is identified by an IP address. The DNS translates human-readable domain names (like google.com) into IP addresses computers can understand.