Energy conversions in a simple electronic device?

Hi, I'm terrible at these sort of things, and to be honest I really don't know what i'm looking at here.

http://www.flickr.com/photos/57195190@N05/6183789665/

The question is :
What are the energy conversions taking place in the sample electronic device? (in the image)

What are the componentry of the sample electrical device, how does each component function in the circuit?

Bit stuck on this one.
Cheers,
Holly.