There are four types of images needed for a GTP iCommerce site. Category Images are thumbnails that represent entire categories of products, for example all electrical goods on the site. Subcategory images are thumbnails representing subcategories of products, all toasters available for example.
Brand images are an image or logo representing the brand of a product.
For example all products by Nike. Product images are pictures of actual specific products. GTP iCommerce is designed to use three sizes of product images. Small or thumbnail images are used to represent the product where detail is not required. Medium images are a standard picture of the product that allow the user to see it in fair detail.