If you search something on Google you may have noticed the long URL in the address bar. These parameters are sent to the Google Servers to give them additional informations about the user and the search.
Here is a sample search URL: https://www.google.at/search?q=person+icon&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:de:official&client=firefox-a&channel=fflb&gfe_rd=cr&ei=e6mRU5DcDYWV_Ab0j4DQAQ
And here is the meaning of the parameters in this Google query:
Q stands for “query” followed by an equals sign and the entered search terms.
IE stands for “input encoding”. It is telling Google what character set was used by the user when he entered the search term.
Stands for “output encoding” and tells Google what character set should be used when return the query result.
Checks, if autocomplete was enabled or not
Gives Google information about what search type the user is using (for example the search box in the browser). Doesn’t appear when using Internet Explorer.
The browser used by the client.
Is basically used to track the user
Tells Google that the search was redirected from a country-specific page
An encoded mix of 4 numbers containing the UNIX timestamp when the search results were served.