Pure Land Buddhism
In the United States and the West, many people approach Buddhism as a philosophy or set of self help techniques. Buddhism can be these things and as it has moved from culture to culture over the last twenty five hundred years, it has been these things and more. These people are often coming from a faith based background and are looking for something more rational, more secular, less overtly religious.
However for most of its history Buddhism has been preserved by institutions which are religious in nature and it has been preserved amazingly well. The Buddha lived at a time when writing had been lost and his teachings were preserved as oral traditions for roughly three hundred years before the earliest texts were written.  In my opinion, oral traditions tend to be more fluid, better suited for preserving the spirit of the teaching rather than the letter of it.
Buddhism teaches that we all have the capacity to awaken as Buddhas and innumerable beings already have done so. In the Mahayana Buddhism one of the early Buddhas to rise to prominence along side the historical Buddha Shakyamuni was Amitabha Buddha, also known as Amitayus. In my opinion, it remains unclear if Amitabha Buddha was a historical figure as we would understand it or a purely mythological one. The texts place his life as being in India hundreds of millions of years ago. However, as I mentioned, this was part of an oral traditions for centuries before it was written down and the Buddha himself studied with the teachers of his day. He was also then heir to an even older oral tradition going back to 1500 BCE or thereabouts.
Regardless, according to the stories, Amida Buddha was once a monk named Dharmakara.
When Dharmakara met the Buddha of his day, he left home life and began studying the Way. Over time, out of deep compassion for sentient beings, Dharmakara made a series of vows. Vows are important in Buddhism. They represent our deepest aspirations and ultimately shape what kind Buddha we become. Every Buddha gets a pure land when he or she attains awakening. It is kind of like a door prize or something. A Buddha's pure land is shaped not only by the vows of the Buddha but also by the kind of world in which he or she resides. Our world is one of the more chaotic worlds so Shakyamuni Buddha's pure land was not very extensive. However, Amitabha Buddha attained awakening in a more conducive environment and fashioned his pure land as a place of refuge for sentient beings who are unable to attain awakening on their own.
The traditional understanding is that we are born there at the moment of our death. Buddhism doesn't talk much about souls but we do talk about consciousness and consciousness according to the traditional Buddhist view survives death and reappears in another form. However, Amitabha Buddha's Pure Land is not exactly heaven. It is more like Buddha Boot Camp. Once born there, we learn the Dharma not only from Amida Buddha but also from countless other Buddhas and Bodhisattvas as well. When we have the tools we need, we return to this and other worlds to help others.
The name Amitabha means 'Infinite Light'. Amitabha is also called 'Amitayus' which means 'Infinite Life'. Somewhere along the long trek out of India, the common portion of the two names were taken as his proper name, Amita or Amida, t and d being linguistically kissing cousins and it is as Amida Buddha that he is known in Japan today. The Pure Land Schoo or Jodo Shu as it is called in Japanesel was offiicially founded in Japan by Honen Shonin in 1175 CE. Together with the closely related Jodo Shin Shu which was founded by one of Honen's students, it remains one of the most popular forms of Buddhism in Japan today.
Figments and Fragments of Mahayana Buddhism: More Collected Papers, 2005, by Gregory Schopen refers to the Mahayana as a religion 'of the book' which arose out of the oral with the development of writing. Approaching the Dhamma: Buddhist Texts and Practices in South and Southeast Asia, 2003, by Anne M. Blackburn makes the case even more explicitly stating that it is “virtually certain that there was no writing system in India at the time of the Buddha.”