Subgraph isomorphism problem

From Exampleproblems

In complexity theory, Subgraph-Isomorphism is a decision problem that is known to be NP-complete. The formal description of the decision problem is as follows.

Subgraph-Isomorphism(G₁, G₂)
Input: Two graphs G₁ and G₂.
Question: Is G₁ isomorphic to a subgraph of G₂?

Sometimes the name subgraph matching is also used for the same problem. This name puts emphasis on finding such a subgraph as opposed to the bare decision problem.

Subgraph isomorphism is a generalization of the potentially easier graph isomorphism problem.