The document discusses different types of plant layouts used in manufacturing units. It describes four main types of layouts for manufacturing: product or line layout, process layout, fixed position or location layout, and combined layout. It notes the key advantages and disadvantages of each. Product or line layout arranges machines in one line based on sequence of operations. Process layout groups similar machines together. Fixed position layout moves equipment, labor, and components to fixed production locations. Combined layout uses elements of the other layout types depending on the manufacturing needs. The document also briefly discusses layout considerations for traders and service establishments.