Hi need some clarification because my site was indexed by google already. I would like to ask if i made additional page to my site does google automatically indexed it?or do i have to submit it again?Please give me some ideas.thanks
You do not need to submit each individual page; Only the first page (top-level page) from a host is necessary;after that Google will find easily your pages.
I think that you won't get any explanations how Google does index websites. It's an algorithm and it's very hard and clear at the same time. We can only know the system of its working, but not the main vector.
It depends on your contents, if it's original and high quality, sure, Google will index it. To make sure, add your new pages to social bookmark websites is a good choice!