Part 1 of Step Patterns: Pattern Axes
Axes make up the first part of step patterns. For example, in the step pattern child::NAME, which refers to a <NAME> element that is a child of the context node, child is called the axis. Patterns support two axes (XPath, on the other hand, supports no less than 13 different axes—see Chapter 7):
The attribute axis holds the attributes of the context node.
The child axis holds the children of the context node. The child axis is the default axis if one is not explicitly set.
You can use axes to specify a location step or path as in the following example, where I use the child axis to indicate that I want to match the child nodes of the context node, which is a <PLANET> element:
<xsl:template match="PLANET"> ...