A Tree is just a restricted form of a Graph.
Trees have direction (parent / child relationships) and don’t contain cycles.
They fit with in the category of Directed Acyclic Graphs (or a DAG).
So Trees are DAGs with the restriction that a child can only have one parent.
One thing that is important to point out, Trees aren’t a recursive data structure.
They can not be implemented as a recursive data structure because of the above restrictions. But any DAG implementation, which are generally not recursive, can also be used.
My preferred Tree implementation is a centralized map representation and is non recursive.
Graphs are generally searched breadth first or depth first. The same applies to Tree.