Difference between Brain-teaser and Riddle

Brain-teaser

Part of speech: noun

Definition: A complex riddle or puzzle.

Riddle

Part of speech: noun

Definition: A verbal puzzle, mystery, or other problem of an intellectual nature, such as "It's black, and white, and red all over. What is it?"A sieve.

Part of speech: verb

Definition: to fill with holesto fill or spread throughout; to pervadeto solve, answer, or explicate a riddle or questionto put something through a sieve

Example sentence: Life is a succession of lessons which must be lived to be understood. All is riddle, and the key to a riddle is another riddle.