Burn Meter Help!?!

Hello Fellow CCs!  I am obviously new to this site and am having a hard time understanding the Burn Meter.

I walked yesterday for an hour and the big number in the middle went up.  What is that number? 

I tried looking through FAQs and couldn't find anything that gave a good explanation of the Burn Meter......can someone help me better understand it?

Thanks in adavance!!

It is how many calories you will burn for the day and it rises when you add more activity and burn more calories based on your age, weight, and activity level you entered when you joined.

In small print, you'll find your overall estimate for a 24 hour period based on the information you entered.  The large number is the estimated number of calories that you've burned in the current day and it goes up as time goes by or as you enter activities.