Sea floor involves plates under the ocean moving farther apart and colliding with continental plates that are then pushed away or toward each other.

The question says,'seaf floor involves plates under the ocean moving farther apart and colliding with continental plates that are then pushed away or toward each other. The answer is sea floor spreading. It usually occur at middle ocean ridge where new oceanic crusts are formed as a result of volcanic activity. After this formation, the newly formed oceanic crust gradually move away from the ridge.