Various levels of TCP/IP protocol stack and their respective functions

network Interface Layer : This is the lowest layer of the protocol stack, corresponding to the OSI physical layer and Data link layer, the main completion of the actual data frame transmission and reception.
Network layer : The process of grouping activities in the network, such as Routing and forwarding, this layer mainly includes IP protocol, ARP, ICMP protocol and so on.
Transport Layer : The main function is to provide communication between applications, this layer is mainly the TCP/UDP protocol.
Application layer : Used to deal with specific applications, for different applications to provide different protocols, such as the FTP protocol for file transfer, send email to the SMTP and so on.

Various levels of TCP/IP protocol stack and their respective functions