In the world of networking, there are literally hundreds of protocols. Some deal with the physical aspects of how wires plug together, such as the RS-232C protocol that specifies the shape, size and number of pins in connectors. These connectors allow modems to plug into motherboards. Voltage levels and methods of bit encoding are part of the protocol (or standard as it is often called.)

Other protocols are at a higher conceptual level, such as the famous TCP/IP protocol suite (set of protocols that form one coherent system.) When the bits arrived through the hardware interface into the computer, they are stored in main memory so that the CPU can interpret them appropriately.