What Is a Computer Network?
What Is a Computer Network? A computer network is a setup that joins a lot of separate computers together to share resources and information. User communication is made easier by the integration of computers and other devices.
A collection of two or more interconnected computer systems is referred to as a computer network. Cable or wireless media can be used to create a network connection. Computers and tools are connected in any network using hardware and software.
A computer network is made up of different types of nodes. Nodes in a computer network can include servers, networking equipment, personal computers, and other specialized or general-purpose hosts. Network addresses and hostnames are used to identify them.
How does a computer network work?
The switches, routers, and access points that make up a computer network are specialised hardware.
Switches link PCs, printers, servers, and other devices to networks in households or businesses while also assisting with internal security. Access points are switches that enable wireless connections between devices and networks.
Routers serve as dispatchers and link networks together. They assess the information that needs to be delivered across a network, pick the optimal routes for it, and then send it on its way. Routers assist shield information from external security risks while connecting your house and business to the outside world.
While there are many differences between switches and routers, one significant one is how they identify end devices. A Layer 2 switch uses the “burned-in” MAC address of a device to uniquely identify it. A Layer 3 router uses a network-assigned IP address to identify a device’s network connection specifically. Today, routing functionality is present in the majority of switches.
Devices and network connections in a network are uniquely defined by their MAC and IP addresses, respectively. A network interface card’s (NIC) MAC address is a number that the device’s manufacturer assigns to the NIC. The number allocated to a network connection is known as an IP address.
Different types of hardware and software are used to run computer networks. Transmission Control Protocol/Internet Protocol (TCP/IP) is the universal standard for communication in packet-switched networks. A network’s endpoints are each equipped with a special identification that can be used to identify the transmission’s source or destination. The IP address or Media Access Control (MAC) address of the node are examples of identifiers. Switches, routers, servers, personal computers, phones, networked printers, various peripheral computing devices, sensors, and actuators are examples of endpoint nodes that are used for routing. Data transmission between computers is outlined by the Open Systems Interconnection (OSI) concept.
1)Computers, mobiles, and other consumer devices: Users often and directly visit these endpoints. For instance, an email is created using the mail program on a laptop or smartphone.
- Servers: The primary computing and data storage take place on these application or storage servers. The servers receive all requests for particular operations or data.
- Routers: The process of routing involves choosing the network path that data packets will take. These packets are sent by routers between networks in order to get to their destination. They boost the effectiveness of big networks.
- Switches: Repeaters are electrical devices that receive network signals and clean or enhance them, much like transformers are to electricity grids. Repeaters with several ports are called hubs. They distribute the data to any open ports there may be. Bridges are more intelligent hubs that only transmit data to the intended port. A switch is a bridge with many ports. To enable connectivity with numerous network devices, switches can accept multiple data cables.
- Gateways: Hardware components known as gateways serve as ‘gateways’ between two different networks. They could be servers, routers, or firewalls.
2)Links: Links are the transmission media which can be of two types:
- Wired:Coaxial cables, phone lines, twisted-pair cabling, and optical fibres are a few examples of wired technology used in networks. To represent data, optical fibres transmit pulses of light.
- Wireless:Radio and other electromagnetic signals can also be used to create network connections. The term “wireless” refers to this method of transmission. Cellular networks, radio and technology distributed spectrums, as well as communication satellites, are some of the most prevalent instances of wireless links. Spectrum technology is used by wireless LANs to create connections in constrained spaces.
3) Communication protocols
- Network access layer: This layer specifies the physical transport of the data. It covers the method through which hardware transmits data bits over actual cables or fibers.
- Internet layer: This layer is responsible for packaging the data into understandable packets and allowing it to be sent and received.
- Transport layer: This layer makes the connection is reliable and authentic, allowing devices to continue talking to one another.
- Application layer: This layer specifies how high-level apps can connect to the network.
4) Network Defense: While nodes, connections, and protocols serve as a network’s building blocks, it is impossible for a contemporary network to function without protections. When enormous amounts of data are generated, transported, and processed across networks, security is crucial. Firewalls, intrusion detection systems (IDS), intrusion prevention systems (IPS), network access control (NAC), content filters, proxy servers, anti-DDoS devices, and load balancers are a few examples of network security tools.
Types of computer networks:
- Local-area network (LAN):
A local area network (LAN) is a group of linked devices in a single physical space, like a house or an office. From a small home network with one user to a sizable enterprise network with thousands of users and devices, LANs can be small or massive. Both wired and wireless devices may be part of a LAN.
A LAN’s unique feature is that it connects devices that are in a single, constrained region, regardless of size.
Wide-area network (WAN): A WAN connects individual users or numerous LANs over a sizable geographic area. You may think of the Internet as a WAN. In order to execute applications and access critical data, large enterprises use WANs to connect their numerous sites, remote workers, suppliers, and data centres.
Leased lines, cellular connections, satellite links, and other techniques can all be used to establish physical connectivity in WANs.
A network designed for a large corporation, sometimes referred to as an enterprise, must adhere to strict specifications. Organization networks need to be highly accessible, scalable, and robust because networking is essential for the operation of any modern enterprise. These networks can be designed, deployed, debugged, and fixed thanks to the tools available to network engineers and operators.
On its campus, in its branches, and in its data centers, an organization may employ.
Service-provider network: Service providers operate WANs to provide connectivity to individual users or organizations. They may offer simple connectivity, in the form of leased lines, or more-advanced, managed services to enterprises. Service providers also supply Internet and cellular connectivity to their customers.
Networks can be either private or public. While everybody may access the public internet, only those who have been given access credentials can access private and virtually private networks.
Network access control (NAC) systems in the enterprise often employ security policies to regulate access to the company’s network. This means that NAC systems enforce preset business policies and prevent network devices from connecting unless they do so. When installed, NAC systems instantly identify any device connected to a network, classify it based on its kind, and then respond to it in accordance with pre-configured compliance standards put in place by the organization’s security team.
NAC systems provide granular controls over the types and levels of access that are permitted, enabling device access to a network on a customised, per-device basis. Policies that are set forth in a centralised control system provide these controls. In order to regulate network access based on group policies and guarantee that users only have the network access necessary to perform their responsibilities, the majority of NAC systems can also integrate with Active Directory (AD).
Local-area networks (LANs) and wide-area networks are two fundamental types of networks (WANs). LANs use links (wires, Ethernet cables, fibre optics, and Wi-Fi) that carry data quickly to link computers and peripheral devices in a constrained physical space, such as a corporate office, lab, or college campus. A typical local area network (LAN) is made up of two or more computers, printers, and large-capacity disc storage units called file servers. These devices allow any computer connected to the network to access a shared collection of files.
Users can connect with one another, share printers and storage devices, and simultaneously access centrally located processors, data, or programmes thanks to LAN operating system software, which deciphers input and guides networked devices (instruction sets). Users of LANs can connect to WANs and other LANs as well.
Over wider geographic areas, including entire continents, WANs link computers and smaller networks to larger networks. They may use cables, optical fibres, or satellites to connect the computers, although most of their users connect to the networks via a modem (a device that allows computers to communicate over telephone lines). The Internet, a network of networks and gateways connecting billions of computer users on every continent, is the biggest WAN.