Choosing between a steam iron and a steam generator iron depends largely on the size of the garment and the storage space available. Steam irons are more compact, but their larger counterparts are better suited for larger clothes or bedding.
Steam irons also have built-in water tanks, and the steam produced relaxes fabrics and removes creases. The higher the steam output, the smoother the clothes will be. Features vary by model, but steam injection and self-cleaning features are usually standard.
Steam generator irons are better for handling larger piles of laundry and bedding. They have a separate tank that allows them to release more steam at higher pressures, which means you can usually iron out one side of the garment to get rid of deep front and back creases.