Hitbox
The invisible area used for registration of hitting opponents when you attack. The hit occurs when the attacker’s hitbox connects (overlaps) with the defender’s hurtbox.

Hurtbox
The invisible area used for registration of being hit by attacks. The hit occurs when the attacker’s hitbox connects (overlaps) with the defender’s hurtbox.

How they look like

Note: This is very simplified (yet still extremely useful) showcase of how hit- and hurtboxes in SC6 works by TOOLASSISTED.