Scrum is an Agile framework. The most famous one. About 70% of Agile companies are using Scrum, or a combination of Scrum with another Agile system such as XP (eXtreme Programming).
It’s important for you to understand that Scrum and Agile are not the same thing. Agile is a concept upon which many frameworks and methodologies have been created, and Scrum is one of them. In other words, Scrum is a way of practicing Agile in the real world.