Throw angle. Again, I am sure the Thoughts on Table Tennis sight gives great info on this. I am just going to give a small piece of info.
A certain amount of what throw angle is, has to do with the ration between these two factors:
1) Spin
2) Speed
The ration can be expressed like this:
Spin/Speed Ratio = meaning that there is a higher degree of spin in relationship to speed. An example would be T05.
Speed/Spin Ratio = meaning that there is a higher degree of speed in relationship to spin. An example would be Calibra.
When the ratio between spin and speed is such that there is more spin than speed:
1) You will usually get more arc on your shots.
2) It is easier to use the spin to arc a higher ball onto the table.
3) The rubber grabs more in relationship to its catapult so the ball would usually jump off a little higher on a topspin brush stroke.
4) Sometimes a rubber with a high Spin/Speed Ratio is more reactive to incoming spin. Therefore, it can take more touch and higher level technique to utilize the properties of the higher Spin/Speed Ratio. In other words this kind of rubber is usually a poor choice for a beginner.
When a rubber exhibits this high Spin/Speed Ratio, it is often called A HIGH THROW rubber.
When the ratio between speed and spin is such that there is more speed than spin:
1) The spin will effect the arc less because there is more speed than spin so the arc will be flatter.
2) It is harder to use spin to arc the ball onto the table.
3) The rubber catapults the ball more and grabs and therefore spins the ball less so the ball comes off the rubber lower on a topspin shot. This also means you can brush less and make deeper contact more safely.
4) Sometimes a rubber with a high Speed/Spin Ratio is less reactive to incoming spin. This is also not exactly what a newer player wants because of the added speed. But for a higher level player this can sometimes make it easier to control on return of serves and counterlooping.
When a rubber exhibits this high Speed/Spin Ratio, it is often considered low throw. Giving credit where credit is due, PNut did give some of this information. But one of the things that made it hard to listen to the quintessential Physics/Engineer/TT Expert was how fond he was of calling everyone an idiot.
For a beginner/intermediate player, a middle of the road rubber that can do everything well so you can develop all your strokes would be preferable rather than a rubber that was heavy on the Spin/Speed side of things or a rubber that was heavy on the Speed/Spin side of things.
There are drawbacks and advantages to any piece of equipment whether low or high throw, or anywhere in between.