What is the difference between force and thrust ?

Foloowing example pretty much explains the concept of thrust. One  rocket's mass is propelled forward by a thrust force equal to, and opposite of, the time-rate of momentum change of the exhaust mass accelerated from the combustion chamber through the rocket engine nozzle. This is the exhaust velocity with respect to the rocket, times the time-rate at which the mass is expelled, or in mathematical terms:

where:

• T is the thrust generated (force); some texts use the symbol F_th
• is the rate of change of mass with respect to time (mass flow rate of exhaust);
• v is the exhaust velocity.