Full Idea
'Buddha' is not the name of a person, but designates a type. 'Buddha' is Sanskrit for someone who is 'fully enlightened' about the nature and meaning of life.
Gist of Idea
'Buddha' just means a person who is fully enlightened about life
Source
Edward Conze (Intros to 'Buddhist Scriptures' [1959], Ch.1)
Book Reference
'Buddhist Scriptures', ed/tr. Conze,Edward [Penguin 1959], p.19
A Reaction
There seems to be an unexplained rule that there is never more than one Buddha in any generation. This isn't controlled by gods, so I take it that everyone defers to the most enlightened one, even if they themselves are very advanced in enlightenment.