Forum Moderators: DixonJones
You'll find it in your logs towards the end of each line. Typical examples of UA's include:
Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)
Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0; T
312461)
Googlebot/2.1 (+http://www.googlebot.com/bot.html)
It tells you what browser the visitor to your site is using (in the first two examples), or if the visitor is in fact a spider bot (as in the third googlebot example).
The Unique User Agent mentioned by Wild_Cujo can be seen by Googlebot. Only Googlebot has the UA above - no other browser *should* be using it (though sometimes people forge the details, but thats for another thread).
JP