Like for example, if I want to find something about Yellow Labs or weather pictures, I think I will get it, but if I search for something political, will the results be biased towards my beliefs, what Ive search for beforehand, or will Google give me a cross section of what Im looking for. Or will it be 'filtered'.
Does this explain when I Google for something on one of my Macs or my husband's or my brother's Mac, that I get different results on each?
The short answer is "it depends."
The long answer is...well, complicated.
If you have a Google account (meaning a G+ account, a Gmail account, an iGoogle account, or anything like that), and you are signed in to it, Google may customize your search results based on things that you have clicked on in the past.
If you have a Google account but you're NOT logged in, it's not entirely clear what happens. If your browser has cookies that ties it to your account, I've heard some people claim that Google may still personalize your results, and some people claim that it doesn't. (I don't think Google documents what happens in that case.)
If you're browsing and you don't have a Google account, or you've wiped the Google cookies off your browser, Google doesn't personalize your results.
That's different from filtering them, however. Google does many kinds of filtering.
The most obvious kind of filtering is Safe Search. If you turn Safe Search on, Google filters out sexual search results. If you have Safe Search turned off, it doesn't.
There are other kinds of filtering, too. Google filters out Web sites that use certain types of unethical search engine optimization; for example, they may remove Web sites that participate in pay-for-play link exchanges or that feed different results to search engine spiders and to human Web visitors.
Google also filters out Web sites which they have received DMCA copyright complaints against, or which they have been informed contain certain kinds of illegal content such as child porn. Whenever this happens, they place the complaint on a Web site at
www.chillingeffects.org and when you do a Google search, you'll see a notice on the bottom of the screen that some Web results were removed for legal reasons.
In non-US countries, Google filters out content as required by local law. In China, Google filters out searches related to Taiwan. In Thailand, Google filters out Web sites that insult the King of Thailand.
Google has lots of rules, which are rather convoluted, about what sites are considered "news," and sites may be removed from Google News results if they do not conform to those rules.
Google filters out sites that do not meet its "quality guidelines," which means sites that are comprised mostly or entirely of ads, or sites which simply reproduce content from other sites.