Difference between %install and %files section in rpm building ?

Hello,

I am just a newbie and have very recently started building rpms, i build a very simple rpm that packaged 3 files and everything worked very smoothly. However to be very honest i am not very much clear with what is the difference between %install and %files section.

I mean like we specify the same files in both the sections then what is the difference and what is the need of specifying the files in both the sections. I read some articles also but could not understand exactly.

So if we any one can explain me rpm building process step by step in a bit detail, like what each section is meant for and what all we need to specify in what section i would greatly appreciate it.

I tried a lot to clear my doubts myself but somehow it is not very much clear so i am hoping somebody would surely help me out here.

Thanks in advance.
Rohit