Galvanized steel pools are constructed with steel that has been dipped several times in a zinc solution to make it corrosion and rust free. The zinc provides a protective layer for the steel, making it capable of withstanding large amounts of moisture. The more times the steel is dipped in the zinc, the more rust and corrosion resistant it becomes. Eventually this material can break down and rust, but not for years, if ever.
Resin pools are composed of a synthetic plastic that will not rust or corrode. Resin provides a clean look that can last for a long time without fading and continue looking like new. Resin pools typically cost more than galvanized steel pools and are just as sturdy.
In an above-ground family swimming pool, kids jump off the ladder, play volleyball and swim back and forth. The walls can take a beating. Steel pool walls have a greater sense of give and bounce back better than resin walls. Under extreme weather conditions, both hot and cold, resin pools risk cracking.
Resin has a more modern and softer feel than steel pools. Most resin pools have countered the premature cracking issue with a UV coating that is meant to relive stress associated with hot weather that can cause the pool to crack. Whether you choose resin or steel, have it installed properly, take care of it and the pool should last you many years.