frames refer to animation frames. iirc, DOA4 runs at 60 frames per second.
in movelists, the frame #s indicate how many frames of animation each part of the move takes. again a lot of this is from memory, but in the DOA movelists the three numbers correspond to execution/hit detection/recovery if i remember right.
as an example...looking at Kasumi's DOA3 frame data (as posted at
DOATEC.com), her P is listed as 9/2/13. so you would read this as:
9 frame execution - it takes this move 9 animation frames to activate. think of this as a sort of 'wind up' period.
2 frame hit detection - the move is active for 2 animation frames. this period is when the move actually connects and will hit your opponent.
13 recovery - for 13 frames after the move is finished, Kasumi is in recovery and can't do anything (...i think. someone correct me if that's not the case.)
DOACentral has a lot of frame data & explanations. just run a search in their game system section. i haven't been there for awhile but their resources are very good and go into a lot of detail.