The market taxonomy of Polymer Nanomembrane types classifies products into flat‑sheet, tubular, hollow‑fiber, composite, and functionalized variants, each addressing distinct process constraints. Flat‑sheet membranes, typically produced by roll‑to‑roll casting, dominate the market due to their ease of module integration and low capital cost. Tubular forms, fabricated by extrusion, are preferred for high‑temperature, fouling‑prone streams because of their self‑cleaning geometry. Hollow‑fiber membranes, with high surface‑area‑to‑volume ratios, support compact module designs in gas separation and dialysis. Composite membranes combine a thin selective polymer layer with a supportive substrate, optimizing permeability while maintaining mechanical strength. Functionalized membranes incorporate nanoparticles, ionic groups, or responsive polymers to impart selectivity for specific ions or stimuli, expanding applications into smart filtration and targeted drug release. Each type contributes proportionally to the overall market, with flat‑sheet and composite categories together representing the bulk of sales, while functionalized solutions capture niche, high‑margin growth.