The term "replacement parts" refers to components or pieces that are used to repair, maintain or restore a product or machine. These parts may be necessary when certain components become worn out, damaged or broken due to normal wear and tear, accidents or other reasons. Replacement parts can vary depending on the type of product or machinery they are intended for - ranging from small screws and bolts to entire assemblies or systems. They are often available from manufacturers, dealerships or distributors, either new or refurbished, to ensure that the functionality and performance of the product or machine is restored to its original condition.