The Types dimension classifies seaweed‑derived hydrocolloids into four commercially dominant families. Agar—extracted from red algae—offers high gel strength and is primarily used in microbiological media, confectionery gels, and vegan desserts, supporting roughly one‑third of total type‑level demand. Carrageenan, also sourced from red seaweed, exists in κ, ι, and λ variants; its ability to form thermoreversible gels makes it indispensable in dairy, meat, and beverage formulations, representing the largest share at about 40 % of type consumption. Alginate, derived from brown algae, provides viscosity and film‑forming properties, finding application in dairy stabilisation, encapsulation, and meat binders, contributing approximately 20 % of the market. Porphyran and other emerging polysaccharides, though niche, are gaining traction in functional foods for their prebiotic effects, accounting for the remaining 10 % of type‑level volume. This taxonomy clarifies how each hydrocolloid type underpins distinct functional roles and influences overall market dynamics.