A computer network is a collection of interconnected computers and devices that communicate with each other to share data, resources, and services. To make such communication possible, several hardware and software components work together in a coordinated manner. Each component of a computer network has a specific role, and the efficiency of the network depends on the proper functioning of all these components. The most basic component of a computer network is the node. A node refers to any device connected to the network that can send, receive, or forward data. Nodes include computers, servers, printers, mobile devices, and network hardware such as routers and switches. End-user devices like computers and smartphones are called end nodes, as they originate or consume data, while intermediary devices help in data transmission. Nodes are identified on the network using addresses, such as IP addresses, which enable correct data delivery. Another important component is the server. A server is a powerful computer that provides services, resources, or data to other computers on the network, known as clients. Servers can perform various functions depending on their role. File servers store and manage files, print servers control printers, web servers host websites, and database servers manage large sets of data. By centralizing resources, servers improve efficiency, security, and management of network operations. Clients are computers or devices that request and use services provided by servers. In a client-server network model, clients depend on servers for resources such as files, applications, and internet access. Clients typically have less processing power and storage compared to servers. Their main function is to provide an interface for users to access network services and perform tasks such as sending emails, browsing the web, or accessing shared files. Transmission media is another essential component of a computer network. It refers to the physical or wireless path through which data travels from one device to another. Transmission media can be classified into guided and unguided media. Guided media includes twisted pair cables, coaxial cables, and optical fiber cables. Twisted pair cables are commonly used in local area networks due to their low cost and ease of installation. Coaxial cables offer better shielding and are used in cable television and older networks. Optical fiber cables use light signals to transmit data at very high speeds over long distances and are widely used in backbone networks. Unguided media includes radio waves, microwaves, and infrared signals, which are used in wireless networks such as Wi-Fi and mobile communication. The choice of transmission media affects speed, distance, cost, and reliability of the network. Network Interface