This force diagram depicts a push or pulls exerted on an object due to its interaction with another thing. There are various types of forces. Different force types are classified into two broad categories based on whether the force was caused by contact or non-contact between the two interacting objects. Many physics students mix up weight and mass. The mass of a thing of the amount of matter it contains; the importance of an object is the force of gravity acting on that object, as shown in this type of forces diagram.