The axis specifies which way through the tree structure is required. As with normal directions, the axis specifies which way through the tree structure is required. A location path is an expression consisting of one or more location steps, specifying how to go from one node to another node. One can specify the branch or sequence of branches to walk along. A branch could either be specified by the numbered branch to traverse at a junction or node. Alternatively, one can say that one should take that branch such that the first reachable node on that branch is of a particular type or value.