A contact force is a type of force that occurs when two objects are physically touching each other. This force can arise from various interactions, such as pushing, pulling, or friction. Examples of contact forces include friction, tension, and normal force, which all play important roles in everyday activities. Contact forces are essential in understanding how objects move and interact in the physical world. For instance, when you push a shopping cart, the force you apply is a contact force that helps the cart move forward. Similarly, when you walk, the contact force between your feet and the ground allows you to maintain balance and propel yourself forward.