What is Zen, what are Zen beliefs, and why is it called Buddhism? Please note that i have no idea about what Zen is, and I mean no disrespect to anybody with this question.

I have heard these words "Zen Buddhism", many times, and I'm curious: why it is called or attached to Buddhism, and how did it come to be?

Can someone explain?
'Zen' is the Japanese name of the school of Buddhism that originated in China around the 5th century AC, called (in Chinese) Chan Buddhism, and whose founder is thought to be Master Bodhidharma, an Indian monk. Later, in the XIIIth century, Master Dogen introduced this species of Buddhism into Japan, where it is mostly practiced today, alongide with the USA and Europe.

It is a form of Buddhism because, among other things, it acknowledges the Way of the Buddha as a way to Awakening; because there is a traceable heritage that links today's Zen Masters with the historical Buddha; and because it emphasizes the practice of sitting meditation ('Zazen') as a way to achieve 'Satori', the Awakening.

There are various schools among the Zen tradition, but the more important today are the Soto and the Rinzai schools. Each of these schools emphasizes different aspects of the Buddhist heritage, and though their ceremonies and mindsettings somewhat diverge, they converge in the emphasis they make on Zazen as a practice that provides, when constantly and earnestly taken upon, an insight into the nature of the Self and the ultimate unsubstantiality of reality.