Breathable membranes are materials designed to allow moisture vapor to escape while preventing liquid water from entering. This makes them ideal for use in outdoor clothing, tents, and building materials, as they help keep the interior dry and comfortable. The technology is often used in products like Gore-Tex and eVent. These membranes work by utilizing microscopic pores that are small enough to block water droplets but large enough to let water vapor pass through. This property helps regulate temperature and humidity, making them popular in both fashion and construction for enhancing comfort and durability.