Crib parts what are the metal rails called that holds up the sides of the crib?

The metal rails that hold up the sides of a crib are typically referred to as "crib side rails" or "side rail supports." These rails are crucial for providing stability and safety, ensuring that the sides of the crib are securely attached and can withstand the weight and movement of the baby. In some designs, they may also be called "crib hardware" or "crib rail brackets," depending on their specific function and construction.