XPath Axis Family Tree Analogy

 The major XPath axes follow family tree terminology:

• self:: is you.

Downward:

• child:: are your immediate children.
• descendant:: are your children, and their children, recursively.
• descendant-or-self:: (aka //): are you and your descendants.

Upward:

• parent:: is your mother or father.
• ancestor:: are your parent, and your parent's parent, recursively.
• ancestor-or-self:: are you and your ancestors.

Sideways (consider elements earlier in the document to be younger):

• previous-sibling:: are your younger siblings, in age order.
• following-sibling:: are your older siblings, in age order.
• previous:: are your younger siblings and their descendants, in age order.
• following:: are your older siblings and their descendants, in age order.

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• child:: will select the immediate descendants of the context node, but does not go any deeper, like descendant:: does.
• following:: will select all of the nodes that come after the context node and their descendant's, but that does not include the context node's descendants.
• descendant:: will select all of the nodes along the child:: axis, as well as their children, and their children's children, etc..

Sometimes, a picture is worth a thousand words: