like what should i be looking at in frame data
A frame trap is a blocked sequence of moves where there’s left a little gap where opponents can press buttons. However, the gap is generally so small that any non-invincible move your opponent does will be counter hit out of.
For example, with Ryu / E.Ryu, the sequence c.LP - c.MP is a frame trap. c.LP is +2 on block, c.MP has 4 frames of start-up, so it’s not a true block string - there’s a 2 frame gap where your opponent can push buttons. However, any move they try to do during that gap that starts up in 3 frames or more will get beaten.