In graph theory, a "tree token" isn't a standard term. It sounds like a creative concept for a game, puzzle, or a simplified explanation of a data structure.
A tree, in this context, is a specific type of graph: a connected graph with no cycles. Think of it as a branching structure, like a family tree or the file system on a computer. Nodes are connected by edges, but you can only get from one node to another via one unique path. There are no loops or multiple ways to get to the same place.
A "tree token" could represent a movable item on this tree structure. Perhaps it can be moved from one node to an adjacent node by following an edge. The rules of a hypothetical game might involve moving this token to a specific location, visiting a certain number of nodes, or collecting other tokens from different branches of the tree. The token's movement would be constrained by the tree's unique, non-cyclic path structure.$TREE