So what exactly is a network ? You most likely encounter networks on a daily basis. Take Facebook for example. It’s called a social network. There are millions of people on this network connected by “being friends” with each other on Facebook. You are probably a part of this network and are connected to your friends on the network. A network is a set of relationships or connections. Try drawing a picture of how you and 5 classmates are connected on Facebook. If you don't use Facebook, create a network of you and 5 classmates. Connect yourselves on the network if you have had any other math classes besides Alg II together. Check out the example below to get an idea on how to create a network. Then click on the image above to choose how to connect your nodes. The dark black line that appears when you click the gray line means that the nodes are connected. Networks are everywhere around us and can be used in many different ways. Let's take a look at how we can mathematically define networks.