Chapter 2 Graph Theory and Some Basic Concepts

The following is not originally from me, but my notes from reading Network Science (Ch. 2.1-2.3) by Albert-László Barabási. Notes are accompanied by my explanations.

What is a network composed of? How is a network different from another one? In this chapter, we are going to study some very basic concepts of network science: size of a network, number of links, degree, average degree, degree distribution, and adjacency matrix.