The pleura is a thin membrane that surrounds the lungs and lines the chest cavity. It consists of two layers: the visceral pleura, which is attached to the lungs, and the parietal pleura, which is attached to the chest wall. This structure helps protect the lungs and allows them to expand and contract smoothly during breathing. Between these two layers is a small space filled with pleural fluid, which reduces friction as the lungs move. The pleura plays a crucial role in respiratory health, and any issues, such as pleurisy or pleural effusion, can lead to discomfort and breathing difficulties.