Upon making the first contact, the ball is passed too far away for anyone to make a second contact, resulting in the opposing team earning a point.
When the team receiving the serve either shanks the serve or after a teammate makes the first pass, no one on the receiving team can make a second. If a second contact is made, it is not considered an ace.
When the team that possessed the serve loosed the point and the receiving team becomes the serving team.
Putting the ball back on the opposing side and they cannot return it, resulting in a point. This can be done in many ways, i.e. an attack, a dump, or even a free-ball.
Putting the ball over in an aggressive way that is not a tip or attack. This move is typically used by setters on the second contact.
Typically done when attempting to set the ball and instead of contacting with both hands simultaneously, the hands contacts separately. This is sometimes can be hard to determine but is frequently detected by the side-spin it produces.