To start with Buddha, where does the word Buddha come from? The word Buddha comes from Siddhartha Gautama. This gentleman was born in 563 BC in southern Nepal, near the border with India. Siddhartha was not just anyone, he was the prince of the Shakya Clan.
All his life he has been looking for the path of enlightenment. For this he gave up his title of prince and left his wife and newborn son, in order to attain enlightenment through fasting and meditation. He hoped that if he reached the state of enlightenment, he would be able to put all living beings out of their misery. Severely malnourished, he realized that what he was doing was not the right way.
With this awareness, he sat under the bodhi tree, where he entered a deep meditation that lasted for 49 days. At the end he reached the path of enlightenment and he now understood what you had to do and what not to do, in order to walk this path.
He was 35 years old when he realized it and then chose to travel through Northern India to teach his teachings, the path of enlightenment. He did this until his death, Siddhartha Gautama or Gautama Buddha turned 80 years old.
His teachings are called Dharma in Asia, the teaching of the enlightened, and are still practiced to this day.
Buddha is thus one who has realized complete and complete enlightenment. Buddha descended from a person, but nowadays by the word Buddha we do not mean a person, but the highest state of consciousness.