The toilet lid is the part that covers the toilet seat and bowl. It is usually sold attached to the toilet seat with bolts and falls down to cover up the inside of the toilet. While this piece is mainly for aesthetic purposes, providing the toilet with a cleaner and sleeker look, it also helps prevent any spray back of water when flushing the toilet.
This piece interacts closest with the toilet sit and toilet bowl, as it is directly attached to both. The toilet lid is an extremely versatile piece, coming in many shapes, sizes, and colors to accommodate the actual installed toilet feature. Unlike the toilet seat, the lid is rounded out, and cannot take the same amount of pressure. Sitting down on the lid or resting any heavy item on the lid can cause it to bow or cause the bolts to crack, making the lid slide around or entirely snap off from the seat and bowl entirely.