Class 25 covers different types of clothing, footwear and headgear. If you own a clothing brand and sell your goods online and in stores, it is sufficient to register in Class 25. The registration will stop any third party from copying your brand name in connection with different clothing items. It doesn't matter if they sell these items online or in stores; you'll have legal grounds to stop them.
You could consider applying for Class 35 if you sell clothes from other brands. For example, you have an e-shop selling sports clothing by Nike and Puma. If you want to protect the name of your store, Class 35 will prevent anyone from creating an e-commerce/retail business with an identical or confusingly similar name in a given jurisdiction.
You can consider applying for Classes 25 and 35 if you have a store that sells a combination of goods, your own and those produced by other brands. This way, you can protect both aspects of your business.
If you are unsure what classes to select for your trademark application, try our free lawyer's check, where our lawyers recommend classes based on your business offering.