What is Understanding of networking protocols and models?

the famous networking protocol we used is tcp/ip that for our networking if you go for a wan internetworking protocol (tcp/ip/udp/snmp/)like wise but for that every protocol follows the osi layed model which are

application layer

presentaiton layer

session layer

transport layer

nertwork layer

data link layer

physical layer

through which your data transfer this is the way your data travel from host to destination