I would suggest you consider this story, it has an answer to your question
A Brahman called Dona encountered the Buddha shortly after his enlightenment and, struck by the Buddha?s serenity, asked him:
?Sir, are you a god??
?No, Brahman.?
?Are you an angel??
?No, Brahman.?
?Are you a Sakha?
?No, Brahman.?
?Are you a human being??
?No, Brahman.?
?When asked, ?Are you a god?? you answer, ?No, Brahman?? When asked, ?Are you an angel?? you answer, ?No, Brahman..? When asked, ?Are you a Sakha?? you answer, ?No, Brahman?? When asked, ?Are you a human being?? you answer, ?No, Brahman?? Then what sort of being are you??
?Brahman, the defilements by which ? if they were not abandoned ? I would be a god: those are abandoned by me, their root destroyed, made like a palm tree stump, no longer subject to future arising. The defilements by which ? if they were not abandoned ? I would be an angel? a yakkha? a human being: those are abandoned by me, their root destroyed, made like a palm tree stump, no longer subject to future arising.
?Just as a blue or red or white lotus born in water, grows in water and stands up above the water untouched by it, so too I, who was born in the world and grew up in the world, have transcended the world, and I live untouched by the world. Remember me, brahman, as a Buddha.?
PS. So who do you think Buddha is: Human, God, Angel, etc.? After answering this question, the question "What Buddhism is" should not take you long to answer
PPS. My opinion: Buddhism is lifestyle, religion...everything actually and at the same time nothing.