How do regex objects work in Python loops?

I am constructing an if statement on Python that prints something when regex's match function founds a coincidence. I would like to know why the if statement works when my statement's condition is not a boolean (I think so).

import re

coincidence = re.match(r'\w{3}', 'abc')

if coincidence:
  print('There\'s a match')

which yields:

"There's a match"

Why does it work?