Resultant Force = overall unbalanced force

Any resultant force produces acceleration 

Force (N)  = Mass (kg) x Acceleration (m/s₂)

F=ma

Force is measured in Newtons (N)

Example 1

A car travels at a steady speed… the thrust force is equal to the drag force.

This does not necessarily mean that the car is stationary, but it does mean that the car is neither accelerating nor decelerating.

Example 2

A car accelerates from rest.

The forward thrust is larger than the backward drag.

The car will accelerate in the direction of the greater force, in this case the forward thrust