The blue OLED display gives information on steps, calories, distance and a picture showing overall activity level
Fitbit is an activity monitor which conveniently clips to pants, shirt or wristband and pays careful attention to what you are doing. It counts your steps, records distance traveled and tells you how many calories you've burned. When you're not being active it'll record data on how long it takes you to fall asleep, how many times during the night you awoke and how much sleep you actually managed to get. Go within a few feet of its base station and it will automatically upload the data to a website for subsequent detailed analysis and storage.