Hitbox

Hitbox
A hitbox is the area of an attack that is able to damage your opponent.

Disjointed Hitbox
A disjointed hitbox is when the hitbox is not attached to the character. A few examples would be Marth, Roy, and Link's sword. A disjointed hitbox, if attacked, cannot hurt the character. For example, If Marth attacks Ness's PK Fire with his F-smash, Marth will not be affected. But, if Mario punches the PK Fire, he will sustain damage.