What is fundamental difference between item.Axes.GetDescendants() and item.Axes.selectitems() in sitecore

Question

What is fundamental/Performance difference between item.Axes.GetDescendants() and item.Axes.selectitems() in sitecore?

Answer 1

item.Axes.GetDescendants() get all the descendants of the item using Sitecore API. It calls item.Children, and then for each child again child.Children recursively. And it adds all those items to an array.

item.Axes.Selectitems(string query) executes Sitecore query passed in the argument in the context of the current item.

So those 2 methods are completely different.

Answer 2

item.Axes.selectitems() selects the items based on query provided.It is always good idea to use item.Axes.selectitems() in sitecore instead of GetDescendents as Get Descendents always fetch the child items recursively and has huge performance hit if child items are large in size.