Worn cushion cloth, low cushions, chalk on the cue ball, uneven cushion rubber are all things that can make cushions unpredictable and can cause bouncing (when a ball rebounds off the cushion at a faster speed than expected). Realistically, we can not play on match table conditions all of the time, so we have to learn to adjust to less than ideal conditions. If you know that a cushion is sometimes bouncing, then allow for it. This can be quite frustrating, as if it does not bounce, then your shot may be short. However, taking the example of a middle pocket loser, it is much better to leave a long loser afterwards than leave the object ball in baulk.
Spring occurs on perfect tables and is purely to do with the ball mechanics. When the object ball is very close to a cushion and it is knocked on to the cushion, it will often spring. The reason for this is that the object ball will skid initially, and if it impacts the cushion whilst still skidding, it will rebound more quickly than normal.
This is a term used to describe a ball taking a path closer to the cushion than expected. It occurs with new cloths.
Impact square-on to a cushion
If a ball is rolling when it hits a cushion it will skid for a while after rebounding, then it will start to roll again.
Surprisingly, a cue ball hitting a cushion with backspin will also skid for a while after inpact with the cushion, and then start to roll.
The cue ball may skid slightly on rebounding, but will start to roll much more quickly than with normal roll or backspin. (With stun/skid there is no rotation at contact with the cushion so ball-cushion friction does not apply).
When playing cushion-first cannons that require the cue ball to run through slightly after impact with the first ball, stun should be used.
When playing cushion-first cannons that require a stun off the first ball, then it is normally best to use top on the cue ball.