If you have enabled the Google Search History feature then every time you search for anything via Google then it will be stored and you can browse this data at a later date. At some point when you sign up for a Google account you will be asked if you want to enable the Google History feature which can be enabled or disabled at any time. The cool thing about this is everything you do will be tracked so if you visited a site a month ago but you cannot remember specifically what it was you can actually go back in your Google History to obtain the details about that site so you can visit it again. Google History will also allow you to know how often you have searched for a certain term, how many terms you searched for each day on Google, or how many web pages visited every day via Google.
In case you’re not using it already, Google’s web history is a free and handy way to find useful links that you forgot to bookmark. I use it quite a bit when when I google search bugs and installation problems that I need to look up later. It can keep track of (1) all of your Google web searches and links you visited from those searches, and optionally (2) all of your web history (not just Google searches)