In English, we don't have a related word, but in the Slavic languages, you can see the same root used for waking up from sleep; in Polish, a budzik is an alarm clock!
In common usage, Buddha refers to Gautama Buddha (Siddhartha Gautama), the founder of Buddhism. You can read more about Gautama Buddha at Wikipedia. Buddhism began in India, and some Hindus regard the Buddha as an incarnation of the god Vishnu.
The image below shows a Buddha carved in the Bojjannakonda monuments in Andhra Pradesh, India: