Learn in the textbookBasics of Graph Theory
DefinitionA node (ノード) is the English-derived name for a vertex of a graph, and it refers to exactly the same thing.
ExplanationIn IT, devices connected to a network and the elements of data structures such as trees and lists are also called nodes. All of them are elements placed at the ends of connections, so they play the same role as the vertices of a graph.
Memory hookThe English word node originally means a knot. Picture the knots where the threads of a net cross.