A collision occurs when two or more objects come into contact with each other, often with force. This can happen in various situations, such as when cars crash on the road or when a baseball hits a bat. Collisions can cause damage to the objects involved and may lead to injuries for people nearby. In physics, collisions are classified into two main types: elastic and inelastic. In an elastic collision, the total energy and momentum are conserved, meaning the objects bounce off each other without losing energy. In contrast, an inelastic collision results in some energy being transformed into other forms, like heat or sound, often causing the objects to stick together.