1. Battery: This shows the current charge on your battery in percentage form to one decimal place.
2. Health: Shows the condition of your battery. The older your battery and the more use it has had, the lower it's health will be. Improper charging and bad maintenance will further reduce your battery's health.
3. Cycles: A charge cycle means using all of the battery’s power, but that doesn’t necessarily mean a single charge. For instance, you could use your notebook for an hour or more one day, using half its power, and then recharge it fully. If you did the same thing the next day, it would count as one charge cycle, not two, so it may take several days to complete a cycle. Batteries have a limited amount of cycles before they are considered to be consumed. Once consumed, a replacement battery is recommended. This is because battery life and overall system performance can be greatly affected after a battery is consumed. More info here: http://support.apple.com/kb/HT1519?viewlocale=en_US&locale=en_US
4. Age: Shows how old your Mac's battery is. This is the exact age from when the battery was installed in your Mac when it was constructed.
5. Temperature: Quite simply the temperature of your battery at that time. You can toggle between Fahrenheit and Celsius.
6. Power Usage: This shows as 'Charging' if your Mac is plugged into a MagSafe charger and otherwise shows a Watt power level if it is not charging. For more detailed information on what Power signifies, please check here: http://negergy.com.au/blogs/news-reviews/5842594-macbook-pro-laptop-power-consumption-review