I am not sure what these types of graph are called, but they remind me of trees, except there is no root, or at least I don't see it. So is there a name for graphs that look like this? I imagine there are several different way to classify it. The more answers, the better.
This is called a brainstorming diagram or mind map: https://datavizcatalogue.com/methods/brainstorm.html
They are used to classify ideas related to the original subject.
It can be thought of as a style of tree diagram where the root is the subject, branches are topics, and leaves are ideas.