CS 02 Lesson 1.docx

CS 02 Networks and Communications I Unit 1 **Lesson 1: Definition and Components of Computer Networking** Computer networking is a cornerstone of modern technology, enabling the interconnected systems that power the Internet, business communications, and everyday digital interactions. Understandi...

CS 02 Networks and Communications I Unit 1 **Lesson 1: Definition and Components of Computer Networking** Computer networking is a cornerstone of modern technology, enabling the interconnected systems that power the Internet, business communications, and everyday digital interactions. Understanding the fundamentals of computer networking is essential for anyone involved in technology, from enthusiasts to professionals. This article will explore the basics of computer networking, including network types, components, protocols, and essential services like the Domain Name System (DNS). Computer Networking **What is a Computer Network?** A computer network is a collection of interconnected devices that share resources and information. These devices can include computers, servers, printers, and other hardware. Networks allow for the efficient exchange of data, enabling various applications such as email, file sharing, and internet browsing. **How Does a Computer Network Work?** Basics building blocks of a Computer network are Nodes and Links. A Network Node can be illustrated as Equipment for Data Communication like a Modem, Router, etc., or Equipment of a Data Terminal like connecting two computers or more. Link in Computer Networks can be defined as wires or cables or free space of wireless networks. The working of Computer Networks can be simply defined as rules or protocols which help in sending and receiving data via the links which allow Computer networks to communicate. Each device has an IP Address, that helps in identifying a device. **Basic Terminologies of Computer Networks** **Network**: A network is a collection of computers and devices that are connected together to enable communication and data exchange. **Nodes**: Nodes are devices that are connected to a network. These can include computers, Servers, Printers, [Routers,](https://www.geeksforgeeks.org/introduction-of-a-router/) [Switches](https://www.geeksforgeeks.org/types-of-switches-in-computer-network/), and other devices. **Protocol**: A protocol is a set of rules and standards that govern how data is transmitted over a network. Examples of protocols include [TCP/IP](https://www.geeksforgeeks.org/tcp-ip-model/), [HTTP](https://www.geeksforgeeks.org/http-full-form/), and [FTP](https://www.geeksforgeeks.org/file-transfer-protocol-ftp-in-application-layer/). **Topology**: Network topology refers to the physical and logical arrangement of nodes on a network. The common network topologies include bus, star, ring, mesh, and tree. **Service Provider Networks**: These types of Networks give permission to take Network Capacity and Functionality on lease from the Provider. Service Provider Networks include Wireless Communications, Data Carriers, etc. **IP Address**: An IP address is a unique numerical identifier that is assigned to every device on a network. IP addresses are used to identify devices and enable communication between them. **DNS**: The [Domain Name System (DNS)](https://www.geeksforgeeks.org/domain-name-system-dns-in-application-layer/) is a protocol that is used to translate human-readable domain names (such as www.google.com) into IP addresses that computers can understand. **Firewall**: A [firewall](https://www.geeksforgeeks.org/introduction-of-firewall-in-computer-network/) is a security device that is used to monitor and control incoming and outgoing network traffic. Firewalls are used to protect networks from unauthorized access and other security threats. **Types of Enterprise Computer Networks** **LAN**: A [Local Area Network (LAN) ](https://www.geeksforgeeks.org/types-of-area-networks-lan-man-and-wan/)is a network that covers a small area, such as an office or a home. LANs are typically used to connect computers and other devices within a building or a campus. **WAN**: A [Wide Area Network (WAN)](https://www.geeksforgeeks.org/wan-full-form/) is a network that covers a large geographic area, such as a city, country, or even the entire world. WANs are used to connect LANs together and are typically used for long-distance communication. **Cloud Networks**: [Cloud Networks](https://www.geeksforgeeks.org/cloud-networking/) can be visualized with a Wide Area Network (WAN) as they can be hosted on public or private cloud service providers and cloud networks are available if there is a demand. Cloud Networks consist of Virtual Routers, Firewalls, etc. These are just a few basic concepts of computer networking. Networking is a vast and complex field, and there are many more concepts and technologies involved in building and maintaining networks. Now we are going to discuss some more concepts on Computer Networking. **Open system: **A system that is connected to the network and is ready for communication.  **Closed system**: A system that is not connected to the network and can't be communicated with. **Types of Computer Network Architecture** Computer Network falls under these broad Categories: **Client-Server Architecture**: [Client-Server Architecture](https://www.geeksforgeeks.org/client-server-model/) is a type of Computer Network Architecture in which Nodes can be Servers or Clients. Here, the server node can manage the Client Node Behavior. **Peer-to-Peer Architecture**: In [P2P (Peer-to-Peer) Architecture](https://www.geeksforgeeks.org/what-is-p2ppeer-to-peer-process/), there is not any concept of a Central Server. Each device is free for working as either client or server. **Network Devices** An interconnection of multiple devices, also known as hosts, that are connected using multiple paths for the purpose of sending/receiving data or media. Computer networks can also include multiple devices/mediums which help in the communication between two different devices; these are known as [Network devices](https://www.geeksforgeeks.org/network-devices-hub-repeater-bridge-switch-router-gateways/) and include things such as routers, switches, hubs, and bridges.   **Network** **Topology** The [Network Topology](https://www.geeksforgeeks.org/types-of-network-topology/) is the layout arrangement of the different devices in a network. Common examples include Bus, Star, Mesh, Ring, and Daisy chain.  Network Topology **OSI Model ** OSI stands for [Open Systems Interconnection](https://www.geeksforgeeks.org/layers-of-osi-model/). It is a reference model that specifies standards for communications protocols and also the functionalities of each layer. The OSI has been developed by the International Organization For Standardization and it is 7 layer architecture. Each layer of OSI has different functions and each layer has to follow different protocols. The 7 layers are as follows:  [Physical Layer](https://www.geeksforgeeks.org/physical-layer-in-osi-model/) [Data link Layer](https://www.geeksforgeeks.org/data-link-layer/) [Network Layer](https://www.geeksforgeeks.org/network-layer-services-packetizing-routing-and-forwarding/) [Transport Layer](https://www.geeksforgeeks.org/transport-layer-responsibilities/) [Session Layer](https://www.geeksforgeeks.org/session-layer-in-osi-model/) [Presentation Layer](https://www.geeksforgeeks.org/presentation-layer-in-osi-model/) [Application Layer](https://www.geeksforgeeks.org/application-layer-in-osi-model/)