These are the important concepts that are mentioned below :- 1.Definition of Computer Networks 2.Nodes 3.Basic Characteristics of C.N 4.Data Flow and its types 5.Definition of Protocols and its elements 6.Message Formatting and Encapsulation 7.Message Delivery Options and its types 8.Peer to Peer Networks and Client Server Networks 9.Components of C.N 10.Classification of C.N(LAN,MAN,WAN,SAN) 11.New Trends in C.N 12.Network Topologies and its types 13.IP Address and MAC Address 14.IPV4 Address 15.Definition of Analogy 16.Port Address OR Port Numbers 17.Three Main key points to Remember 18.Switching Techniques in C.N and Block Diagram 19.Approaches in Packet Switching 20.Role of Protocols In Layering 21.Two Layered Architectures 22.Layers In OSI Reference Model 23.Simple technique code of remembering the Layers 24.Working of Layers. 25.Brief Explanation on OSI Reference model of all layers 26.Services Provided on All Layers. 27. Short and Basic definitions of different layers of OSI Reference model 28.Working of OSI Reference Model 29.Port Adderessing and IP Addressing and its working 30.Working of TCP/IP Model 31. 4-Layered architecture of TCP/IP Model 32. 5-Layered architecture of TCP/IP Model 33. Short and Basic definitions of different layers of TCP/IP Model. 34.Block Diagram of TCP/IP Protocol Suite 35.Some Basic and Useful Abbreviations of Data Networks And Protocols 36.Protocol Data Unit (PDU)