Distinguish between balanced and unbalanced forces.

Hint: At a time, several forces can act on a body. Draw a free body diagram and analyse the resultant force on the object.

Complete step by step answer :
A force is a push or pull on an object resulting from the object's interaction with another object. Although, the interaction is not necessarily physical contact. For example, gravitational force. A body can have several forces acting upon it at an instant of time. Since, force is a vector. All the forces acting on a body can be added vectorially to find a resultant force or net force the body experiences. This quantity determines if the forces are balanced or unbalanced.
Balanced forces: As the name suggests, the resultant or the net force acting on the body is zero. Essentially, it means that the forces balance each other. When there is no force on a body, acceleration becomes zero as well. Which implies that the velocity of the body does not change or that the body retains its state of motion.
For example, a heavy box lies on the floor and a person is unable to move it even by applying a greater force each time. This is because the frictional force balances the applied force each time.
Unbalanced force: When the net force acting on a body is non zero and an acceleration exists, the force is said to be unbalanced. This implies that the velocity of the object is varying.
For example, a box, placed on a smooth surface, is being pulled by two people applying constant force from the opposite sides. Now, the person with more strength (who applies more force) will drag the box to his side with an acceleration (non-uniform velocity). Thus, one can say the forces are unbalanced.

Note: Firstly, it is assumed that the object is not massless. And its mass does not vary. Secondly, the force vector can lie anywhere in space, i.e. all the forces vectors need not lie in 1D or 2D, they can lie in 3D as well.