The physical layer is responsible for the physical transmission of data bits over a network medium, such as copper wire, fiber optic cables, or wireless signals. This layer deals with the electrical or optical encoding and decoding of data, signal modulation and demodulation, and synchronization between devices. The physical layer is also concerned with the physical connectivity and topology of the network, including cables, connectors, and network cards.
2. The Data Link Layer:
The data link layer provides reliable data transfer between adjacent devices on a network. It is responsible for error detection, flow control, retransmission mechanisms, and addressing at the network interface level. The data link layer operates over the physical layer and typically includes protocols such as Ethernet, Wi-Fi, and Point-to-Point Protocol (PPP). It ensures that data is successfully transmitted and received between nodes, without errors or missing packets.
3. The Network Layer:
The network layer provides routing and addressing at the packet level, allowing data to be transmitted between hosts across multiple interconnected networks. This layer is responsible for determining the best path for packets to travel through a network, managing traffic flow, and preventing network congestion. The network layer also provides support for different network protocols, such as Internet Protocol (IP) and Address Resolution Protocol (ARP), enabling different types of networks to communicate seamlessly with each other.
