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# Networking Fundamentals
## What is a Network?
A network is a group of two or more computing devices connected to share resources and exchange information. These devices can include computers, servers, printers, routers, and other hardware devices. Networks can be connected through wired or wireless connections and are built using hardware and software components, such as routers, switches, access points, and operating systems or applications.
## **Two common categories of computer networks**
### **Client-Server networks**
In a client-server network, one or more central servers provide services to multiple client devices. Clients, such as desktop computers, laptops, and mobile devices, request resources or services from the server, which responds. This type of network is commonly used in businesses and organizations, where central servers can provide services such as file storage, email, and database management.
### **Peer-to-peer (P2P) networks**
In a P2P network, all devices are considered equal and can communicate directly, without a central server. Each device can act as both a client and a server, sharing resources and data with other devices on the network. This type of network is commonly used for file sharing and collaboration and is often seen in home networks and small businesses.
## **Types of Network.**
### **1. LAN (Local Area Network)**
A LAN is a network that connects devices within a relatively small geographical area, such as a home, office, or campus. LANs are typically used to share resources such as printers and files and can be connected using wired or wireless technologies. A switch is typically used to connect devices in a LAN.
### **2. CAN (Campus Area Network)**
A CAN is a network that covers a larger geographical area than a LAN, typically serving sites such as colleges, universities, and business campuses. CANs can be connected using technologies such as fibre optic cables and L3 switches.
### **3. MAN (Metropolitan Area Network)**
A MAN is a network that covers a larger geographical area than a LAN or CAN, typically covering a single city or region. MANs are typically used by organizations such as universities and businesses to connect multiple LANs. A router is typically used to connect devices in a MAN.
### **4. WAN (Wide Area Network)**
A WAN is a network that connects devices over a larger geographical area, such as between different cities or even countries. WANs are typically used for communication between remote sites and can be connected using technologies such as leased lines, satellite links, and VPNs. A router is typically used to connect devices in a WAN.
A **Node** or **Host** refers to any device that is connected to a network and is capable of communicating with other devices on the network. Each node typically has a unique identifier, such as an IP address or a MAC address, which enables it to be identified and communicate with other nodes on the network.
