In Equilibrium of concurrent force system, all forces are meet at a point of a body. But if the forces acting on the body are not meet at a point, then the force system is called as Non-concurrent force system.
In concurrent force system we find the resultant and its direction. Because all the forces are meet at one point so the resultant will also pass through that point, i.e. the position of resultant is already clear. But in nonconcurrent force system we find the magnitude, direction and distance of the resultant from any point of the body because forces are not meet at single point they act on many point of the body, so we don’t know the exact position of the resultant. For finding out the position of resultant we used the concept of moment.
