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The computer network enables multiple computer devices to communicate with each other. This communication occurs through data exchange and resource sharing between the devices. This article list and explain the critical components, key terms and topics of Computer Network. We have covered over 100+ terms.
Introduction
A computer network is established by connecting devices using a wired or wireless media. These interconnected devices follow certain rules to send or receive data for communication. These rules are known as communication protocols. These protocols are necessary to avoid collisions during communication and maintain data integrity. Also, they make sure the data packets reach to the right destination.
Several components are needed to build a computer network. With the help of these components, a computer network can create reliable and secured communication channels for multiple devices. These devices include, laptops, PCs, printers, scanners etc. These are end devices directly used by the users.
Computer Network Terms
Some basic concepts are necessary to know in order to understand how a computer network is developed and how it works. These terms are described below:
| Terms | Description |
|---|---|
| Network Types | PAN, LAN, MAN, WAN |
| Personal Area Network(PAN) | This type of network is built when one person connects multiple devices for personal use. |
| Local Area Network(LAN) | Multiple devices within a limited area are connected through one common communication media creates this type of network. |
| Metropolitan Area Network(MAN) | Connecting different LAN, this network covers a city, or metropolitan area using a shared communication media. |
| Wide Area Network(WAN) | WAN connects smaller networks and expands it to a larger network over a larger area such as, large cities, and countries. |
| Network Topologies | Bus, Ring, Star, Mesh, Hybrid |
| Bus | One single cable connects multiple devices. |
| Ring | Devices are connected to the devices next to them, forming a ring. |
| Star | Devices are connected to one single hub or switch. |
| Mesh | Every device is interconnected to each other. |
| Hybrid | Combining two or more topologies to create a network. |
| Computer Devices | These are the end devices that the users use. Such as, PCs, laptops, mobile, printer, scanner, tablet etc. |
| Network Interface Card(NIC) | This connects the devices with each other on a network and controls the communication flow. |
| Switches | Switches connects multiple devices to the network and ensures the data packets being received at the right destination. |
| Routers | Routers select the best route on a network for the data packets to reach their destination. |
| Hub | A hub distributes the network connection among the devices. It controls the communication between devices on a network. |
| Port | It is used as a channel for sending and receiving data. |
| Transmission Modes | Data transmission between devices occur in three ways: Simplex, Half-duplex, and Full-duplex |
| Simplex | In this mode, data flows in one direction only. It means, devices can either send or receive data, but cannot do both. For example, a radio channel. Here, data is sent to the audience but not received back. |
| Half-duplex | In this mode, data flows in both direction but not the same time. It means, devices need to wait to receive after sending the data. For example, a Walkie-talkie. Here, data is sent from one end and the receiver wait to receive before replying. |
| Full-duplex | In this mode, data is bi-directional. Sender and receiver both can communicate at the same time. For example, a telephone. Here, data can be sent and received simultaneously. |
| Network Protocols | A network follows many protocols and standards to control the flow of communication. Some common protocols are, HTTP, HTTPS, TCP/IP, UDP, DHCP, POP, FTP, SMTP, Telnet. |
| Hyper Text Transfer Protocol (HTTP) | It is designed for tranferring information between a web browser and a web server. |
| Hyper Text Transfer Protocol Secure (HTTPS) | It has the same functionality as HTTP except the information is encrypted. |
| Transmission Control Protocol (TCP)/Internet Protocol (IP) | It is used for connecting devicese and communicating over the internet. |
| User Datagram Protocol (UDP) | It functions similar to TCP but the communication is much faster. |
| Dynamic Host Configuration Protocol (DHCP) | It is used for assigning IP addresses and other configuration information to netowork devices. |
| Post Office Protocol (POP) | It is designed for receiving mails from the server for the client. |
| File Transfer Protocol (FTP) | It is designed for tranferring files from one device to another. |
| Simple Mail Transfer Protocol (SMTP) | It is used for transferring mails from client to server. |
| Teletype Network (Telnet) | It is used for establishing virtual communication channel between two devices. |
| Network Models | The entire network communication process relies on network models. The two most broadly used models are OSI model and TCP/IP model. |
| Open Systems Interconnection Model (OSI) | It is a seven layers: Application layer, Presentation layer, Session layer, Transport layer, Network layer, Data Link layer, and Physical layer. |
| OSI - Application layer | It provides network resources to the users. |
| OSI - Presentation layer | It translates, compresses, and encrypts data. |
| OSI - Session layer | It establishes, manages, and terminates the sessions. |
| OSI - Transport layer | It safely delivers messages and error from process to process. |
| OSI - Network layer | It moves packets from source to destination. |
| OSI - Data Link layer | It transfers data frames from hop to hop. |
| OSI - Physical layer | It transmits bits over a communication media. |
| Transmission Control Protocol/Internet Protocol Model (TCP/IP) | It has five layers: Application layer, Transport layer, Network layer, Data Link layer, and Physical layer. |
| TCP/IP - Application layer | It enables users to interact with the network. |
| TCP/IP - Transport layer | It controls a reliable data flow between hosts. |
| TCP/IP - Network layer | It delivers packets from source to destination. |
| TCP/IP - Data Link layer | It transfers data frames between devices. |
| TCP/IP - Physical layer | It uses transmission media to connect the devices and setup the network. |
| Communication Media | There are two types of communication media: Guided and Unguided. |
| Guided Media | It is referred to the physical medium used for transmission. Such as, Twisted pair cable, Coaxial cable, and Optical fibre cable. |
| Unguided Media | It refers to the wireless media used for transmission. Such as, Radio waves, Microwaves, and Infrared. |
| Multiplexing | Multiple data can be combined and processed through this single media. |
| Demultiplexing | This medium separates the combined data into a single one at the receiver's end. |
| Switiching | This process forwards messages from one computer network to another. There are three switiching techniques: Circuit Switching, Message Switching, and Packet Switching. |
| Circuit Switching | It establishes a reliable communication between two devices through a physical media. |
| Message Switching | It transfers an entire message as a data from the source to the destination. |
| Packet Switching | It creates smaller parts or packets of a message before transferring them to the destination. |
| Error | During data transmission, data may sometimes be corrupted and cause some error to the received message. There are three types of errors that can occur; Single Bit Error, Multiple Bits Error, and Burst Error |
| Single Bit Error | Only one bit is corrupted in this error. |
| Multiple Bits Error | More than one bits are corrupted in this error. |
| Burst Error | More than one consecutive bits are corrupted in this error. |
| Error Detection | There are four techniques for error detection; Single Parity Check, Two-dimensional Parity Check, Checksum, and Cyclic Redundancy Check. |
| Single Parity Check | In this method, one redundant bit is added to the original data to check for errors. |
| Two-dimensional Parity Check | In this method, a row and column of redundant bits are added to a block of bits to calculate and check for the error. |
| Checksum | In this method, the data is split into fixed portions and these portions are summed up using 1's complement at the receiver's end to check for errors. |
| Cyclic Redundancy Check | In this method, the data is divided using binary division and sent as a codewords. The receiver applies same method on the codewords and checks for the error. |
| Error Correction | The errors that occur during data transmission are corrected using two methods; Backward Error Correction and Forward Error Correction |
| Backward Error Correction | In this process, the receiver requests the sender to retransmit the data. |
| Forward Error Correction | In this process, the receiver uses error-correcting code for automatic correction of errors. |
| IP Address | Every device connected on the internet has a unique IP address that indentifies them globally. |
| Internet Protocol Version 4 (IPv4) | It is the fourth version of IP and it provides addresses of 32-bit length. |
| Internet Protocol Version 6 (IPv6) | It is the most recent version of IP and it provides addresses of 128-bit length. |
| MAC Adress | It is a unique address that identifies a device to other devices on a local network. |
| Routing | It is a selection process of finding the data transmission path. There three types of routing; Static Routing, Dynamic Routing, and Default Routing. |
| Static Routing | It requires manual selection of the data transmission or routing path. |
| Dynamic Routing | In this process, protocols and algorithms are used to select a routing path. |
| Default Routing | In this process, the routing path leads to a fixed destination for all data. |
| Domain Name System (DNS) | This system matches easy-to-remember website names to its IP address. |
| Client and Server | It refers to the relationship between a device and a server. An user or client requests information or resource from a device to a server. |
| Gateway | It is a system that connects different networks. |
| Firewall | It is a security measure that monitors the network communication and prevents any threats based on some security rules. |
| Uniform Resource Locator (URL) | It is a subset of URI and it finds the location of an item on the web. |
| Uniform Resource Identifier (URI) | It is a superset of URL and it finds the item on the web using its location or name or both. |
| Virtual Private Network (VPN) | It provides an encrypted connection of a device to a network in order to hide data from the third parties. |
| Proxy Server | It is a server that acts on the user's behalf to send requests and accept data from the web. |
Conclusion
With this article at OpenGenus, you must have a strong idea of different terms in the domain of Computer Network.
A computer network requires devices, transmission media, protocols, and defenses to maintain proper network communication. Each of these concepts help to better understand the foundation of a network and how it works. This article only provides a brief idea on these components. But as the network is advancing in this modern world, a deeper understanding of them is necessary to utilize them to our benefit.
