machine.config ??

I'm swotting up for my 70-305 and have noticed example questions on the machine.config file but despite the fact I have Microsofts book on the above exam there is little mention of this file.

Is it important ?
Should I spend time syudying up on it ?

Thanks in Advance guys

http://www.15seconds.com/issue/030115.htm

I Love Frogs;)

Jimi Hendrix :)