what is googles actual search function

so as almost most do myself also use Google a lot and I keep doing research on Google search box and try different search quires with manipulation and replacing position of words so i try and see how Google search function works and what it is, i.e how they search for text in web pages and how they sort the results,i need any example and/or search technique available,no matter what you think i would like to look at it and see it,this is because i don't know how they search text for millions of pages and how they sort them so any example is well accepted, I also know about web crawler and indexer Pagerank and Hits algorithm but i don't mean that,what i mean is in the actual Php or c++ code what are the actual functions that deliver the job and find results (i.e what the secret algorithm that they hide could be?) looking to hearing from you