Earth is not greatly expanding or contracting. Without changing the dimensions of Earth, how could the plates move in
relation to one another?

The movement of the plates creates three types of tectonic boundaries: convergent, where plates move into one another; divergent, where plates move apart; and transform, where plates move sideways in relation to each other. They move at a rate of one to two inches (three to five centimeters) per year.

i think its white blood cells

i hope this