Very importantly, the relationship on networks is that of the server and the client. A server is a computer that holds content and services such as a website, a media file, or a chat application. The server holds that page, and sends it out when requested. A client is a different computer, such as your laptop or cell phone, that requests to view, download, or use the content. A computer network is a telecommunications network that enables sharing of resources and information. Nodes in a network are connected with each other using either cable or wireless media and use a system of digital rules for data exchange. Data is transferred in the form of a packet, a formatted unit of data source.
More often than not client can connect over a network to exchange information. For instance, when you request Google’s search page with your web browser, your computer is the client. For Example two computers are connected together with an Ethernet cable. These computers are able to see each other and communicate over the cable. The client computer asks for a website from the server computer. The website is delivered from the server, and displayed on the client’s web browser. The World Wide Web is the Internet application that catapulted the Internet from a somewhat obscure tool used mostly by scientists and engineers to the mainstream phenomenon that it is today. The Web itself has become such a powerful platform that many people confuse it with the Internet, and it’s a bit of a stretch to say that the Web is a single applications. You could argue that since you already have a way to protect WiFi-based communication you just as well use it to protect the fiber-based channel, but that presumes the outcome of a cost/benefit analysis. Suppose protecting any message, whether sent over WiFi or fiber, slows the communication down by 10% due to the overhead of encryption. If you need to squeeze every last ounce of performance out of a scientific computation (e.g., you are trying to model a hurricane) and the odds of someone breaking into the datacenter are one in a million (and even if they did, the data being transmitted has little value), then you would be well-justified in not securing the fiber communication channels.