Both freebies offer you a chance to play games without spending any funds (e.g., making your deposits), but, as such, they are rather different. A free trial bonus gives you virtual funds to test the game without a chance of winning any money. On the other hand, a no deposit bonus is a welcome package offered by a casino, and as such, it gives you the possibility to win some cash, although it comes with specific wagering requirements you have to meet.