A Fiberglass pool is one-piece assembly made of fiberglass material. They are pre-fabricated in a factory to certain height, weight, and depths. When delivered, they are ready to be installed. That being said, they are the quickest pool type to be installed.
Gunite pools are made of sand, water, and cement making it extra durable. Unlike fiberglass pools, gunite pools can be made on-site which allows for more flexibility and an easier install. There are also several finishes that can be applied allowing for different variations of texture.
A pool liner completely overlays the pools walls and floor creating an impenetrable surface. The primary purpose of the liner is to provide a leak-proof barrier to retain the water within the pool while providing a decorative look. The liner is not a permanent addition. It attaches to the swimming pool, therefore can be removed for repair or replacement.