Networks are everywhere. Be it the network of friends in a university or the online social networks such as Facebook and Twitter or the transportation networks or financial networks, networks are ubiquitous in human society. A network is a collection of objects (nodes) with relationships / interconnections (edges) between them.
Since networks are so universal, analyzing them gives us valuable information about different complex phenomena. For example, by analyzing a network of people in an organization, we can find out the most influential people in that organization. Or by analyzing a network of different airports or train stations we can find out which places have the maximum risk of spreading a particular virus. Network analysis provides us with the tools that will help us answer these type of questions.