If people fear one thing about Google, it's that Google might invade their privacy in some way. That's a natural fear. As Google creates more and more services, it can gather an increasing amount of information about you. And there are also worries that Google tracks all of your searches, and it could then easily create a personal profile of you and sell the results to the highest bidder.
But here, in a nutshell, is the scoop: When you create a Google account, you need to enter basic informationyour email address and password. Google doesn't share that information with any other website.
When someone visits a Google site or does a search using Google, Google servers record information about that visit, including the IP address of the visitor, the URLs, and the date and time of the request.
IP address A unique number, such as 188.8.131.52, that identifies each computer that uses the Internet. The IP address of your computer is typically assigned by your ISP when you connect to the Internet. Your ISP changes your IP address each time you connect, and if you have an always-on connection (such as with a cable or DSL modem), your ISP also changes the IP address occasionally.
Google doesn't use that information to build a profile of you or track the searches you do; this information stays on Google's servers. By itself, that information doesn't identify you because Google, by itself, can't match an IP address to an individual. Law enforcement officials, however, can subpoena that information, and they can use it to identify you and the searches you do. They can subpoena your ISP and find out the subscriber name of the person with the IP address at a given time. So based on Google logs and information provided by your ISP, law enforcement officials can identify you and what you do on Google. Google complies with subpoenas.
Cookie A small bit of data put on a computer that identifies a person and can store personal preferences and other information.
In addition, Google shares what it calls "aggregated non-personal information" with other companies. This aggregated information is information that Google records but that isn't tied to an individual. So, for example, it might collect information about what pages are most popular among Google visitors. It aggregates information from many people's Web-surfing activities to get this information. But it doesn't track any single individual's use.