Why the site can "blink" when you click on the links?

Tell me, please, why when you click on the links, for example, at zs-tomsk.ru / seen some "blinking" do not know how else to call it. Well, that is to click on the link, a split second you see a white screen and then load the page.

And, for example, here (or website community.modx-cms.ru / ) this is not blinking - a cap and design of the site is always visible, even when the page is loaded.