A catch on a door closer is a mechanism that is used to catch or receive the door closer as the door is closed. This mechanism is usually located on the inside of the door and is designed to prevent the door closer from being damaged when the door is closed. The catch can be a simple piece of rubber or plastic that catches the door closer when the door is closed, or it can be a more advanced mechanism that catches or supports the door closer in a certain way. The catch is designed to ensure that the door closer continues to work smoothly and to prevent the door closer from being damaged or falling apart.