We know that interconnected data can be represented as a network. In network analysis theory, we study the details of the methodologies developed to explore and analyze data represented as a network . Let's look at some important aspects of network analysis theory in this section. 

First, note that a vertex in a network acts as the basic unit. A network is an interconnected web of vertices where each connection represents the relationship between various entities under investigation. It is important to quantify the usefulness and importance of a vertex in a network in the context of the problem we are trying to solve. There are various techniques that can help us quantify the importance. 

Let's look at some of the important concepts used in network analysis theory.