An applied force is a force that is exerted on an object by a person or another object. This force can cause the object to move, stop, or change direction. For example, when you push a shopping cart, the force you apply helps it roll forward. Applied forces can vary in strength and direction. They can be constant, like when you hold a book in your hand, or they can change, like when you pull a sled up a hill. Understanding applied forces is essential in physics, as they play a crucial role in how objects interact with each other.