Final answer:
Siddhartha Gautama is known as the Buddha because he achieved enlightenment while wandering the Kingdom of Magadha.
Step-by-step explanation:
Siddhartha Gautama is known as the Buddha because he found enlightenment while wandering the Kingdom of Magadha. He meditated under a Bodhi tree and achieved enlightenment, which means he gained deep insight and understanding of the nature of life and the way to end suffering. As a result, he became the awakened one, or the Buddha.
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