Short answer: yes
Every trademark application has to state the products and services it will cover. This matters because a mark cannot be registered if it is purely descriptive or generic for those goods or services. For example, "CAR" cannot be registered for vehicles. A mark also cannot be too close to one that already exists. HAMASON for an online bookstore, for instance, would be refused because it is too similar to Amazon.
Not sure which class fits?
If you can't tell which class or classes match what you offer, consider ordering the Trademark Study from Marcaria.com. Our experienced attorneys will review how you describe your products or services and match them to the most suitable class or classes for your business.