What are the 4 layers of TCP IP?

The TCP/IP model consists of four layers, each playing a crucial role in the transmission of data across networks:

1. Application Layer: The topmost layer in the TCP/IP model, the Application Layer, interacts directly with end-user applications. It provides network services directly to user applications, enabling tasks such as file transfer, email communication (SMTP, POP3), web browsing (HTTP), and remote access (SSH, Telnet). This layer is responsible for data formatting, encryption, and compression specific to each application protocol.
2. Transport Layer: Layer 4 of the TCP/IP model, the Transport Layer, ensures reliable end-to-end communication between devices on a network. It uses protocols like TCP for reliable, connection-oriented communication with features such as error correction, flow control, and sequencing of data packets. UDP, another protocol at this layer, provides connectionless, unreliable transport for applications requiring speed over reliability, such as VoIP and online gaming.
3. Internet Layer: Also known as the Network Layer, this third layer of the TCP/IP model is responsible for addressing, routing, and fragmenting data packets across interconnected networks. It uses the Internet Protocol (IP) to encapsulate data into packets and determine the best path for data transmission based on network conditions and destination addresses.
4. Link Layer: The bottom layer of the TCP/IP model, the Link Layer, handles the physical connection to the network hardware and manages data transfer between devices on the same local network segment. It includes protocols such as Ethernet for wired networks and Wi-Fi for wireless networks, ensuring reliable transmission of data frames between nodes.

The TCP/IP model employs these four layers to provide a structured framework for network communication, from application-level interaction to physical network transmission. Each layer contributes specific functions and protocols to enable efficient, scalable, and reliable data transmission across diverse network environments, including the internet.