This is my user agent
Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.64 Safari/537.31
I know I am
User Agent string provide information on application type, operating system, software vendor / version and layout rendering engine.
Depending on browser you would also get additional information. IE provides Feature Tokens that contains information about .NET runtime versions. You can learn more about IE specific tokens here - http://msdn.microsoft.com/en-us/library/ms537503(v=vs.85).aspx
Not sure if you would need this but will surely help to understand how user agent strings are decoded - http://www.texsoft.it/index.php?c=software&m=sw.php.useragent&l=it