I see. But what does the i-notation in front of the numbers in that thread mean? Also, what do the plus and minus signs mean?
The i stands for impact frames, the lower the number, the faster the move. It tells you how many frames it takes for a move to come out after you input its command. Therefore, the frame data I linked you to lists the moves in order of fastest to slowest (i11 to i28).
The numbers listed after H, C, and B, indicate whether you're in advantage or disadvantage on Hit, Counterhit, and Block, respectively. + means advantage, - means disadvantage. You have to finish your move animation before you can do another action (block, sidestep, another attack, etc.) and frame advantage/disadvantage lets you know how quickly you get back to your ready stance compared to your opponent.
Take a look at Sieg's standing, plain old K.
i13: K
H: +2
B: -8
On hit, K gives Siegfried frame advantage of 2. This means he recovers 2 frames faster than his opponent and is in a good position to counterhit or force a mix up. On block, K puts Sieg at 8 frames of disadvantage, meaning the opponent will recover 8 frames before him.
There isn't a value listed for C, so that means it has no special properties as a counterhit and merely does the same thing as on hit (+2).
Some moves knockdown (KND) or stun on hit/block and that's listed instead of frame advantage/disadvantage in those cases.