The Sanskrit word Amitābha is an honorary title used for the King of our spiritual world Sukhāvatī (Skt.), situated in the stellar system Sirius (Skt. Margavyadha).
The term Amitābha combines two Sanskrit words अमित(amita), which translates as immeasurable and भा(bha)(abha)(abhati), which translates as light. Lord, or King Immeasurable Light is the ruler of the spirit-heaven known to us as Sukhāvatī. His title speaks to the bright light that flows from him. Humans learned about Amitābha in the 1st century, a time when the Hellenistic and Greco-Roman gods were still very active. Hellas, the sun god was the god of light of that era and some may have been ready to once-again syncretise the gods but there was a major difference between the fierce creator god Hellas and King Immeasurable Light. The King is not creator of the material world, does not interfere in it, and is a creature himself.
Amitābha is an ancient spiritual being who, at some point in time aeons ago, was but a soul being like us. It was long ago, before this Earth school was in operation, perhaps in other worlds, on a different planet. One of the honorific titles of the Amitābha is Tathágata, which means “one who has thus gone” or one who has walked this path of ours. Amitābha rose through the ranks of spiritual growth until he/it (spiritual beings have no gender) became what some call a perfected all-wise spiritual being, therefore a Buddha, a god. From that station, Amitābha increased in spiritual powers and stature to rise to intergalactic supreme status. He became the head of the splendorous spiritual world of social caregivers, Sukhāvatī.