Class 25 is a product trademark, which is mainly used on clothing, shoes and hats and other goods; Class 35 is a service trademark, which is mainly used for services such as advertising and promoting others. If you are making your own brand and selling it, you will usually register in both categories. If you just open a clothing store and sell other brands of clothing, you will usually register in category 35. But if you think you will make your own brand in the future, you can also Consider registering 25 categories of products as well.