Namespaces are hierarchical representation of entry types. For example, articles.books means books entry type is child of articles entry types.
getByLimit and getByLimit Support
getByLimit support means you can add /first_X, /last_X or /random_X to end of the url to get first, last or random X results.
getByIndex support means you can add /X to end of the url to get Xth result.
X is Integer.