This document provides information about different types of bathtubs, including their history, materials, and features. It discusses the earliest evidence of bathtubs in the Indus Valley dating back to 3300 BC. Modern bathtubs are typically made of acrylic, fiberglass, enamel on steel, or cast iron. Different tub styles include rectangular, oval, corner, two-person, drop-in, freestanding clawfoot, alcove, whirlpool, undermount, and walk-in tubs. The document also compares various tub materials like acrylic, cultured marble, enameled cast iron, enameled steel, fiberglass, and solid surface.