I am searching for a specific keyword in google and from different computers I am getting different results. On one computer, the website I was expecting for is the 3rd on the first page and on other computer, the website is not listed at all in the first page. Is there some cache that I need to clear in order to have the search returning unique results on all computers?
Google's Personalized Search feature uses search history to personalize your search results. Since all searches on Google Search are associated with a browser cookie record, previous search results and visited websites can be used to provide more relevant results.
See "Step 3" of Google's Search and Browse Privately support page to turn off result customization.