Undo tree stores the changes you make in a tree, like Emacs does by default, but its undo function is undo only and its redo function is redo only. When there a

Undo tree stores the changes you make in a tree, like Emacs does by default, but its undo function is undo only and its redo function is redo only. When there are multiple different changes you can redo you can select which one you want. Vundo offers that functionality with Emacs' default undo tree, making it an objectively better package as it preserves undo-in-region, which undo-tree lacks.