In this day and age, a computer that is completely isolated from the outer world is pretty much useless. Many everyday tasks, such as sending or receiving e-mail, sharing files, or querying a database, require an external connection.
In order to communicate, computers use a software component called a network protocol. I won’t go into detail about the different network protocols, as there are already many books on the subject. There are actually many network protocols, but the de facto standard is the TCP/IP protocol.
This protocol was developed in the ’70s by the Defense Advanced ...