Graph learning Introduction
Graphs
Describe objects through their connections.
Before this
No earlier lesson needed. Start here.
The intuition
A graph consists of nodes and edges. Nodes represent entities, while edges represent relationships. Edges can be directed, weighted, or both.
A concrete example
In a citation graph, papers are nodes and a directed edge points from a citing paper to a cited paper. Our prerequisite atlas is also a directed graph.
What to remember
A graph encodes chosen relationships. Missing edges do not always mean there is no real-world relationship.
Check your understanding
Does a connection from A to B necessarily imply a connection from B to A?
Reveal explanation
Only in an undirected graph. Directed edges can represent one-way relationships.