What is a social network, what's a digital footprint, and how does a social network work?

A social network is a network that has many computers all on one server; it allows you to connect with your friends post what you're doing or "What's on your mind?" and you can share photo's with your friends and family. A Digital Footprint is a history of what you've did on that server or on your computer, it's like you "Web History" on your internet explorer. A social netowork works by getting many computers to connect to the same server and then from there allowing you to abide by the rules and regulations of the site.