Distinguish between thrust and pressure

(i) Distinguish between thrust and pressure.
(ii) Why is it easier to swim in sea water than in river water?

(i) Thrust The total perpendicular force exerted by a body on any surface in contact with it, is called thrust.
Pressure The thrust acting per unit area of a surface is called pressure.
(ii) It is easier in sea water because sea water exerts more upthrust on the body than the river water because of its higher density.