Perm is short for permutation for PLL in the Fridrich Method. A J-Perm is one of the possible permutations that you can get, just like with R-Perm, V-Perm, U-Perm, etc.
hi friends ....my name is farhad ... i am fom iran .....i use zz method
my record is 12.5 ....but once i were in luck i had EOline skip and i solved in 10 sec
my favor cube is 3*3*3
i just practice 3*3*3
good luck