The term protocol comes from the Greek \"Protokollon\", which was the cover page glued to a manuscript volume that provided a description of the contents. Just as people use language to communicate, network devices use network protocols to transmit data over a network in order to communicate inside the network. Since the appearance of the data networks, many researchers have focused their efforts on designing and developing many ways to communicate the network devices. This paper will introduce the reader to the network protocols and algorithms that are used for data transfer between devices. The meaning of the terms, their description and their explanation are provided.