what is this last thing you mentioned just now?
It  is the celestial abode (dwelling) of Vishnu.
Vaikuntha
Vaikuntha (, ), Vaikuntha Loka, Vishnuloka, Paramam padam, Nitya Vibhuti, Thirupparamapadham or Vaikuntha Sagara is the celestial abode (dwelling) of Vishnu who is the principal deity of the Universes and known to be Godhead, as revered by all of pre-Battle Of Kurukshetra, and the supreme being in Vedic, Hinduism, and its Vaishnavism traditions. 
what is the relation between kuber and ravan in mythology Kubera is described as the uncle of Ravana in the "Mahabharata". what is this former one worshipped for? He is worshipped as the god of wealth. what significance it has in other religion? In Jainism, he is the attendant Yaksha of the 19th Tirthankar Mallinath. is he a good deity according to the puranas? Yes, as The "Purana"s grant him unquestioned godhood. who is the above mentioned latter god? A king of Lanka and the chief antagonist in the Hindu epic "Ramayana" and its adaptations. where was he born? There are several beliefs, but the people of Bisrakh village in Uttar Pradesh claim that Bisrakh was named after Vishrava, and that Ravana was born there. is he a follower of lord shiva? Yes how is he related to linguistics? He is the composer of the "Ravanabhet" and "Ravaniya". and any medical connection? He is also the composer of the 16th century C.E. scriptures "Nadi Pariksa" and "Nadi Vijnana" on knowledge about the veins. what service did he provide to lord vishnu? As gatekeeper at Vaikuntha.
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Vaikuntha [SEP] Introduction
Vaikuntha (, ), Vaikuntha Loka, Vishnuloka, Paramam padam, Nitya Vibhuti, Thirupparamapadham or Vaikuntha Sagara is the celestial abode (dwelling) of Vishnu who is the principal deity of the Universes and known to be Godhead, as revered by all of pre-Battle Of Kurukshetra, and the supreme being in Vedic, Hinduism, and its Vaishnavism traditions. Vaikuntha is an abode presided over on high exclusively by him, accompanied always by his feminine partner, consort and goddess Lakshmi, According to Ramanuja, "Parama padam" or "Nitya Vibhuti" is an eternal heavenly realm and is the divine imperishable world that is the God's abode. It is the highest state beyond all worlds and nothing else beyond it.