State the OSI model and explain 3 of them. In computing
The OSI (Open Systems Interconnection) model is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven different layers. Each layer in the model represents a specific function that must take place in order for data to be transmitted from one device to another.
1. Physical Layer (Layer 1): The physical layer is responsible for transmitting raw bitstream over a physical medium. This layer deals with the physical connection between devices, including cables, switches, and network interface cards. It defines the physical characteristics of the network, such as voltage levels, data rates, and timing of the transmission.
2. Data Link Layer (Layer 2): The data link layer is responsible for establishing, maintaining, and terminating connections between devices. This layer ensures that data is reliably transmitted over the physical layer by detecting and correcting errors that may occur during transmission. It also provides addressing and error detection mechanisms to ensure accurate delivery of data.
3. Network Layer (Layer 3): The network layer is responsible for routing and forwarding data packets between devices on different networks. This layer is crucial for determining the optimal path that data should take to reach its destination. It also handles addressing and logical network topology, allowing devices to communicate across different networks. The Internet Protocol (IP) operates at the network layer, which is essential for connecting devices in different networks.