Hot melt adhesive, a thermoplastic solid at room temp, bonds surfaces when molten. Components include polymer for strength, resin for bonding, chemical softeners for viscosity, and antioxidants for protection. Benefits: durability, thickness retention, no VOCs, quick drying, cost-effectiveness. Acronal adhesives, pressure-sensitive, find wide use. Differences: hot melt's superior adhesion, higher melting temp, perceived reliability compared to Acronal.