How is the waterproof and breathable membrane waterproof

Waterproofing is the process of waterproofing or waterproofing an object or structure so that it is relatively impervious to water or prevents the ingress of water under specified conditions. These items can be used in wet environments or underwater to specified depths.
Water resistance and water resistance generally refer to the possible penetration of liquid water under pressure, while moisture resistance refers to resistance to moisture or humidity. The penetration of water vapor through a material or structure is reported as a moisture vapor transmission rate.
The hulls of ships were once waterproofed by coating them with tar or bitumen. Modern items can be waterproofed by applying waterproof paint or by using gaskets or O-rings to seal seams.
Waterproofing refers to building structures (such as basements, decks or wet areas), boats, canvas, clothing (raincoats or waders), electronic equipment and paper packaging (such as liquid cartons).