I tired to search many keywords in google.com every time it shows millions of pages as search results but when I tried to browse the last result for the keywords even the search result got short to less than 800 website listing for that particular keyword. You can try any keyword but at the most you would be able to see very less website less than 800 as compared to shown by google millions competing for that search term. Can anyone let me know why such thing happens in google?
Google is filtering supplemental results that's why you're seeing site less than the number of total results
Also, Google knows that no one is going to be searching over 1,000 pages deep in the search results. If you are going 1,000 pages deep on your search and not finding what you are looking for then you have some serious searching deficiencies. The typical user will rarely go past page 3 of the results if they still haven't found what they were searching for. By page 3 they usually try a different search.
That is just a estimate given by them to you that how much information you can get connected to this keyword . If you search for my bike then they will try display all results where these keywords are used in any format or line .