$('ul#tmp li a').click() vs. javascript getElement

$('ul#tmp li a').click() vs. javascript getElement

Say I have a jquery script like this

$('ul#tmp li a').click()

If just use javascript to get the node, I have to get nodes like this

document.getElementsByTagName('ul').getElementbyID('tmp).getElementsByTagNames('li').getElementsbyTagNames('a')

And then define the onClick for each nodes I get?

But in jquery

$('ul#tmp li a').click

Simple codes like this will do?