The avatars are the ones who are born with perfection or are made into perfection in their life time on earth. Their karma are nulled by special ways or they are born to this present time for a specific purpose from the higher realms to aid in upheaval of values or eradication of negative influences by exponential settling down of Karma of masses of souls.
The avatars cannot be distingushed in appearance but only by their deeds.
We would like to go through some of the more popular proposed fures; but it doesn’t mean that they are the only ones !
Sri Rama Krishna
Satya Sai Baba