Computer network
A computer network is a group of two or more interconnected computer systems or other computing devices that can exchange data and share resources. These connections are typically made through physical links like cables or wireless connections using radio waves.
Networks enable communication between users, allow for the sharing of hardware resources (like printers or storage devices) and software applications, and provide access to information stored on other devices on the network. The most famous example of a computer network is the Internet, which is a massive global network of interconnected networks.
Contents
Overview and Purpose
The fundamental purpose of a computer network is to facilitate communication and resource sharing among connected devices and their users. By linking computers and devices, networks allow for:
- Data Exchange: Sending and receiving files, messages (email, chat), and other forms of digital information.
- Resource Sharing: Sharing hardware resources like printers, scanners, or storage devices, and sharing software applications or data files.
- Communication: Enabling various forms of electronic communication between people, such as email, instant messaging, video conferencing, and voice calls (VoIP).
- Access to Information: Providing access to databases, websites, and other information resources stored on networked servers.
Networks vary widely in size and complexity, from a small number of devices connected in a home or office to vast global networks.
Key Components
A computer network typically includes several key components:
- Computers and Devices
- The end devices connected to the network, such as desktops, laptops, servers, smartphones, tablets, printers, and other network-enabled devices.
- Networking Devices
- Hardware that connects and manages the flow of data between devices. Examples include:
- - Hubs: Simple devices that broadcast data to all connected devices (mostly obsolete).
- - Switches: Connect devices within a local network and forward data only to the intended destination device.
- - Routers: Connect different networks (e.g., a local network to the Internet) and forward data packets based on IP addresses to route traffic between networks.
- - Modem: Connects a network (like a home network) to an Internet service provider.
- - Firewalls: Devices or software that monitor and control incoming and outgoing network traffic based on predetermined security rules.
- Transmission Media
- The physical or wireless channels through which data travels.
- - Wired Media: Ethernet cables (twisted pair), coaxial cable, fiber optic cable.
- - Wireless Media: Radio waves used for Wi-Fi, Bluetooth, cellular networks, satellite communication.
- Protocols
- Sets of formal rules and standards that govern how data is formatted, transmitted, and interpreted by devices on the network (e.g., TCP/IP, HTTP, FTP). Protocols ensure that different devices and software can communicate effectively.
How Data Travels
In most modern computer networks, data is broken down into small units called packets. Each packet contains a portion of the data, along with control information such as the source and destination IP addresses, the protocol being used, and sequencing information.
These packets travel across the network, potentially taking different paths, being forwarded by routers and switches until they reach their destination. At the destination, the receiving device's networking software (guided by protocols) reassembles the packets back into the original data.
Types of Computer Networks
Computer networks are often classified by their geographical size and scope:
- Local area network (LAN)
- Connects devices within a small, confined area, such as a home, office building, or campus. LANs typically offer high data transfer rates.
- Metropolitan area network (MAN)
- Connects devices across a larger area than a LAN, typically spanning a city or a large campus. A MAN often interconnects multiple LANs.
- Wide area network (WAN)
- Connects devices over a large geographical area, which can span regions, countries, or even continents. The Internet is the most prominent example of a WAN (or collection of WANs).
- Personal area network (PAN)
- Connects devices within a person's immediate workspace, usually within a range of a few meters (e.g., connecting a phone to headphones via Bluetooth, or a computer to peripherals).
Other types include Storage Area Networks (SANs), Virtual Private Networks (VPNs), etc.
See also
