Saline solution is a mixture of salt and water, typically containing 0.9% sodium chloride. It is commonly used in medical settings for various purposes, such as cleaning wounds, hydrating patients, and delivering medications. The solution helps maintain the body's fluid balance and is safe for intravenous use. In addition to medical applications, saline solution is also used in laboratories and for contact lens care. It can help rinse and store lenses, ensuring they remain clean and comfortable for wear. Overall, saline solution is a versatile and essential fluid in both healthcare and everyday life.