HDL cholesterol stands for High-Density Lipoprotein cholesterol, often referred to as "good" cholesterol. It is important because it helps remove other types of cholesterol from the bloodstream, reducing the risk of cardiovascular disease. Higher levels of HDL cholesterol are associated with a lower risk of heart attacks and strokes. Maintaining a healthy lifestyle, including regular physical activity and a balanced diet, can help increase HDL levels and promote overall heart health.