Steam irons have a tank of water that forms steam at high temperatures. When ironing, this steam is released and due to this, the fabric is smoothed faster. When using conventional irons you will have longer strokes and not all folds can be smoothed out. If you are interested in more about the use of irons, then I advise you to read on this site https://ironsexpert.net/ In addition to articles, there are reviews on different models of irons.