What is the difference between SWA, AWA, and STA cables?

The main difference is the armour material and the type of mechanical protection each design provides.
SWA cable uses steel wire armour. It provides strong mechanical protection and better tensile strength, making it suitable for multi-core armoured power cables, industrial power distribution, underground routes, outdoor fixed wiring, and installations where pulling stress may be involved.
AWA cable uses aluminium wire armour. It is commonly used for single-core AC cables because aluminium is non-magnetic, helping reduce magnetic losses and heating problems that may occur if steel armour is used around single-core AC conductors.
STA cable uses steel tape armour. It provides good protection against compression and external mechanical damage, and is often used for direct burial, ducts, tunnels, and fixed installations where radial pressure is more important than tensile strength. STA is usually not preferred for applications requiring high pulling force. Professional armoured cable guides commonly distinguish SWA and AWA by armour material, weight, magnetic behavior, and suitable cable core configuration.