What is the purpose of a drain lid and how does it contribute to the functionality of a drainage system?

A drain lid is used to cover and protect the opening of a drain. It helps prevent debris, objects, and animals from entering the drain, which can clog the system and cause blockages. The lid also provides a barrier to prevent accidents and injuries from occurring. Overall, the drain lid contributes to the functionality of a drainage system by maintaining proper flow and preventing potential issues.