I think life is existing only on Earth ... that is sofar known to Human. There are 84 lakhs of Varities of Lives existing
in the Universe. . . all together comes to 100 lakhs of Crores of livings on the Earth. . . (human imagination so far )
For every living there are 4 stages in the course of life.... it is mostly for human =>>
1. Child hood life ... early life ...1- 14 years.(Baalyamu in Telugu).
2. Teenage ....youthfull life ... 14- 35 years (Yavvanamu in Telugu).
3. Middla age ... Realizing life.. 35 - 55 years(Kaumaaramu in Telugu).
4. Old age ... Life of lastdays... 55 to till death ( Musalitanamu in Telugu).
---------------------------------------------------------------------------------------------
This is my own classification ... different people say in different ways.