Connectivity is essential for every type of knowledge networks. Knowledge networks evolve over time as know-how improves; it’s typically needed to attach legacy copper-wired serial communications to trendy TCP/IP communications by means of extra superior media comparable to optical fiber. Furthermore, many several types of knowledge codecs, requirements, media and connectors are sometimes combined and used collectively inside a single knowledge community. Examples of several types of requirements and protocols embrace bodily-layer requirements, akin to RS-232, RS-485, RS-422, TTL, USB, and TCP/IP, and better-degree protocols, corresponding to Profibus, Interbus, Modbus, BACnet, and Modbus TCP/IP. Copper wires and optical fibers are typical examples of various media; and there are dozens of various connectors used for machine-to-machine (M2M) connectivity and knowledge communication techniques, together with DB9, DB25, USB sort A, USB sort B, mini USB, micro USB, terminal blocks, RJ11, RJ45, and ST, SC, FC, and LC connectors for fiber optic merchandise. There are four several types of connectivity specifically: Serial, USB, Ethernet and Fiber Optic.