a second is split up in 25 frames, if you cast, block, hit with a weapon or recover from beeing hited, you will see a animation.
For every char and animation there is a base time you need. For example your block animation goes 12 frames. Now you can equip items with faster block rate (fbr) as soon you have enough fbr the animation will only take 11 frames. Then 10 frames and so on. The breakpoint ist the minimum amount needed to get a certain duration
The diffrent types:
Faster hit recovery ( fhr )
Fater block rate (fbr)
faster caste rate (fcr)
increased attack speed (ias)
breakpoint tables look like this
fcr% | fpc
-----------
0-8 13
9-19 12
20-36 11
37-62 10
63-104 9
105-199 8
200+ 7
FCR: Faster cast rate
FPC: Frames per cast
this is for a sorceress and not for all her spells