Definition:Component of Graph

Definition
Let $$G$$ be a graph.

Let $$H$$ be a subgraph of $$G$$ such that:


 * $$H$$ is connected;


 * $$H$$ is not contained in any connected subgraph of $$G$$ which has more vertices or edges than $$H$$ has.

This graph has 4 components:


 * Components.png

If a graph has only one component, it is connected.