Assuming the following keywords in a h1 header (for example):
Red Leash For Dog
Does google compute all keyword combinations such as:
Red Dog For Leash, Dog Leash For Red, ...
Or does it compute substrings such as:
Red Leash, Leash For Dog, Leash For, ....
It seems hard to believe Google would compute all combinations since for a single page, it could easily reach millions.
Anyone knows how multiple keywords are taken into account? Thanks!
You don't need to use all word orders in your website. Google can figure it out. This is due to the way that they search. The create what is called an "index". It works similarly to the index in the back of a cookbook that list ingredients along with page number on which recipes for them can be found. Only with search engines its words instead of ingredients and web pages rather than page numbers.
When you search for a phrase it looks in the index for each of these words and then figures out which pages are in the index for each of the words. Then it has to figure out the ranking among all the webpages that match. It might use word order during this ordering phase.
I'd suggest reading an article about how search engines work such as this one from How Stuff Works: http://computer.howstuffworks.com/internet/basics/search-engine.htm
