Step Patterns
Each step pattern is actually made up of three parts, though only one, the node test, is always required. The three parts are an axis, which indicates a tree relationship between nodes the node test, which specifies the kind of node that the step pattern matches and the predicates, which test these nodes further to see if they match the pattern. You've already seen node tests, such as node , text , and , in action here we'll have a closer look at axes and predicates in step patterns.