Reverse osmosis (RO) membranes are essential components in water purification systems, varying in type, material, and performance. The most common types include thin-film composite (TFC) membranes, known for their high rejection rates and efficiency; polyamide membranes, offering durability and resistance to chemicals; and cellulose acetate membranes, which are more environmentally friendly but less efficient. Choosing the best RO membrane depends on water quality, intended use, and budget. TFC membranes are often favored for residential and industrial applications due to their superior filtration capabilities. Assessing specific needs will help determine the most suitable membrane for optimal water purification.