ABOUT BI & NetWeaver...?

Dear gurus,

i am working in BW from the last 2 years. now i want to learn BI which is relate to Netweaver. please let me know that What is BI actually? so what can i learn for Netweaver which is related to BW.? please send me any documents if any one having on it. it would be gr8 help to me. Awaiting for your valuable inputs.

my mail id is: marialad@gmail.com

Thanks in advance.

Regards

Richa