I heard that Google can track all the static pages in a website and all the text, images, and video in those pages, but how can it track the dynamic pages?
For example, if I search for "Facebook Sam Jerusalem" on Google, it will show search results containing my Facebook page and some related pages, too. Same in the case of Elance, Freelancers.com, DeviantArt, and many other sites. It also works with Stack Overflow: we can search for questions, and Google may find a page on Stack Overflow for that question.
I can't believe that for every user or for every product these sites automatically generate a static page. I searched for the answer but I can't understand what many sites are telling, and some are providing only a vague idea.
How does Google track dynamic webpages?
To a client, there is no difference between a static and a dynamic page. The client simply asks for the content at a URL, and the server gives the content to the client.
Search engines like Google request pages and index them. The server can process the requests however it wants as long as the client still gets the content.
This is an oversimplification, but the details don't matter for the purpose of this question.