Physical forces are interactions that can change the motion of objects. They can be classified into two main types: contact forces and non-contact forces. Contact forces, like friction and tension, occur when objects touch each other, while non-contact forces, such as gravity and magnetism, act at a distance without direct contact. These forces are fundamental to understanding how objects move and interact in our world. For example, gravity pulls objects toward each other, keeping us grounded on Earth. Understanding physical forces helps explain everyday phenomena, from why a ball rolls down a hill to how planets orbit the Sun.