Directed Connectivity: Strong vs Weak & Strong Components | Discrete Mathematics §10.4

The web is a directed graph — links point one way — and studying its reachability revealed a famous "bowtie" shape. Direction changes what connected even means. In this video: connectivity for directed graphs, on the board. A digraph is strongly connected when you can travel from any vertex to any other following the arrows; it is only weakly connected if that works when you ignore the directions. We show a digraph that is weak but not strong, then find its strongly connected components — the maximal sets of mutually reachable vertices. We finish with the web's IN → CORE → OUT bowtie and bridge to counting walks with matrix powers. This video is part of Discrete Mathematics · Graphs (§10.4 — Connectivity). Full section playlist linked above / in the description on the channel. Made with the Engineering Simplified method: a calm, two-voice story lesson taught on a chalk-and-board, with every definition and example drawn out step by step. Topic coverage follows Rosen, Discrete Mathematics and Its Applications (Chapter 10).