This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Old firmware version after android firmware upgrade

Hi

What happens with the old(initial) android firmware version after the new firmware version is installed to a device (successful android firmware upgrade).

Is it completely wiped out ?

Is it stored in some partition ? If yes, then where is it stored? Can we rollback to this old (initial) firmware version ?

If rollback is possible, How can we rollback to the old firmware version?