Dependent Options comes in handy when your website has product options that are depend upon the selection of the parent options. For example: In printing press product, clothing products where customers need to choose color, size, length etc. Dependent options allow you to create different child options based on parent option values for your website products. Create different option values based on selected options of the product.
Dependent options are useful in many aspects where customers need to choose options based on previous option selections, it is very powerful yet useful tool in opencart product options.