What purpose does this solve in selenium

Question

What exactly is the use of "::"? And besides the parent, what other different things can we use it for?

By.xpath("parent::*/parent::*")

Answer 1

Well this is not a Selenium functionality, but rather an XPath functionality. Basically, :: separates an axis name from a node test in an XPath expression. And that above is actually XPath syntax is.

Similar things you can do are:

child::*      ->  Selects all the child elements of the current node
attribute::*  ->  Selects all the attributes of the current node
child::text() ->  Selects the entire text present in the child node of current node
child::node() ->  Selects every child node of the current node