---
tag: ZS3F0KAR1J
kind: concept
name: Source
sources:
  - wikipedia: en:325802@r1373839425
    locator: Glossary of graph theory, section S
    note: adopted
    mention: wikipedia://en/325802#39NU
    sections: [Summary]
inventory: [56GS9H3M7B]
---

## Summary

A source, in a directed graph, is a vertex with no incoming edges (in-degree equals 0).