You know jQuery uses CSS selectors to query the elements in DOM. This mechanism is known as “Selectors API“. “Selectors API Level 1” is W3C Recommendation as of Feb/21/2013. “Selectors API Level 2” is included in “DOM 4” (2015).
The standard way to access the element of the web document is DOM. In web pages, the “document” object is a gateway to all other elements.