Power of Attorney

Hi everone,

Will anybody tell me what is the irrevocable power of attroney? Is this meams that it can not be revoked during the life time of executant?

Or if it can be revoked whether the revocation should also be registered, if POA is registered.

And whether the consent from the attorney is also required or the executant unilaterely can revoke it?

pls answer, thanks in advance

regards,

poonam