Subject: How is rosin used, where does it come from how does a basball player use it

I bought a chunk of yellow-brown rosin at a hardware store.  I want to 
know more than my encyclopedia tells me.  It gives 3 sources - how do 
I know which source mine is from and how it is used in sports?  My 
chunk looks much like a rock but is slightly sticky.  

Re: How is rosin used, where does it come from how does a basball player use it