The dremel. In very simple terms, as I'm not sure what I've just bought..

I have just bought this http://www.amazon.co.uk/gp/product/B...?ie=UTF8&psc=1

but there doesn't seem to be a power source?

do I need a chuck like this http://www.amazon.co.uk/dp/B0002SMMY...I2NMIZUR1M91OE

I feel I'm being very thick and haven't thought this through.

Can anyone help? what else do I need to buy?