In the game of cricket, when the bowler delivers the ball to the batsperson, what makes the action of 'bowling' a legitimate delivery as opposed to 'throwing' the ball (which is called a 'no ball')?

There are several ways a "no-ball" can be delivered but the one with that causes the most angst is where the bowler "excessively straightens the arm" when delivering. A movement of less than 15 degrees is permissible. If such a bowler is called it may lead to him/her ultimately not being permitted to bowl again in a match until "remedial action" is undertaken under supervision.
https://www.sportsadda.com/cricket/features/types-of-no-balls-in-cricket/