, a constructive proof
leaves you with a method
to actually find an instance of the object whose existance is being asserted. By insisting on constructive proof
, existence becomes a stronger notion.
A constructive definition is a definition of (a) mathematical object(s) that can be constructively proved to exist.
At least, this summarizes my understanding of an article on L. E. J. Brouwer in a weekly magazine 20 years ago.