Fundamentals of computer science tutorial (FCST)

 Intro of computer network and needs of OSI model A computer network is a collection of various computing devices. The purpose of computer networks is to enable the devices to share the data. Means, to connect the various devices - various heterogeneous and homogeneous devices. The main purpose of computer networks is to share the data. Now, in computer networks, we have one sender and one receiver. Sender is the one who is trying to send some data to the receiver. The sender and receiver can be a machine. The user sends the data through a machine. So we can say, the sender writes a program to send some data to the receiver. Now, how will the user send the data? It requires some kind of a connection. Connection can be a wired connection or a wireless connection. But first of all the user needs some connection. Through the connection, the packets or the data will move from the sender machine to the receiver machine. Now, the term over there is connection. Next is, the sender...