master page loading and web content page loading

Hi all,

I have an doubt that is the master page loads first or web content page loads first?

in my application some pages are loading after loading the master page load event.and some other pages are loading first and then master page is loading and i want to know the reason. why it is happening like this any reasons are there to load web content page before loading the master page.

if any body knows the reason why it was happening and what is the solution for this problem.

Thanks In advance.

Thanks and regards
V.S.R.K.Raju