Welded wire mesh is a strong, grid-like metal fabric made by welding perpendicular steel wires at each intersection, creating a rigid structure that doesn't fray and holds its shape, used widely for fencing, security cages, reinforcing concrete, gardening, and machine guards due to its durability, versatility, and cost-effectiveness compared to woven mesh. It's available in various materials (steel, stainless, galvanized) and configurations (panels, rolls, different wire gauges) for diverse applications.