Late lunch

Got home mid afternoon and it was time for a late lunch. Sitting in the lounge I discovered I wasn't the only one and it was obviously late lunch for the birds too. This one was backwards and forwards to the feeder.

Is it a Great tit or a Coal tit and how do you tell the difference?

I've just signed up for a 2hr evening photography workshop at the Japanese gardens in Rivington in a few weeks time. Could be fun! Decided it would be something to look forward to and it would be a bit of fresh air.