The period you have lived from your birthday to today
The current period that has not been passed (This can be the current year, month, week, depending on your settings)
The estimated period you have left to live based on the average statistics and the data you entered (gender, country, smoking)
Period from expected to maximum lifespan on the calendar (default 100), you can enter up to 125
The period that you lived longer than expected, based on the average statistics and the data you entered