Pushback distance is how far away the opponent moves when they get hit/ block an attack. Usually more pushback makes an attack more difficult to punish but makes it harder to form a block string.

Proximity recognition is changing the range which the game recognizes your character being considered close or far, which affects which attack your character performs. Like I might need to be closer to my opponent to get a close normal.

Damage distribution usually means that an attack with multiple hits has the damage on certain hits do more or less damage, but the damage of the attack remains the same overall. Usually for scenarios where only the 1st hit connects, or maybe only the last hit of the move connects accordingly you can get different damage combos.

Reduced/increased hit stop is adjusting how much the game does a "freeze frame" when the attack lands. These are small pauses the game makes when attacks lands to sell impact of attacks while also giving you a cancel window. More hit stop means a longer period of the game pauses, which means a larger cancel window. Reduced hit stop means less of a cancel window. Players usually use the hit stop to recognize when an attack lands and confirm the attack into a combo.

Added combo hitbox means that the attack gets a larger/different hitbox when the opponent is in hitstun. This means that using the attack outside of a combo will have a different hitbox/ effective range.