What exactly is the difference between copyright and trademark? How?

Trademarks are the "brand name" of goods. Think - Ford cars & trucks. Tide laundry detergent. Budweiser beer. Copyright protect original artistic creations - books, movies, songs, plays, etc. Copyright does NOT protect slogans. In order to protect your new slogan as a trademark - you need to use it commercially for a product. Good luck.

Copyright protects the expression of an idea. Trade and service marks indicate who the source of a good or service is. Generally, slogans, like book titles, can't be copyrighted. Occasionally, they can be trademarked. There are exceptions, of course. If the slogan is more than just the words, if it includes an original design and the words are part of that design, you probably already have the copyright on it since copyright protection springs up as soon as an original work is fixed in a permanent medium. You're not required to register it with the U.S. Copyright Office but you can; it doesn't cost much and it adds a little bit more protection.

1. You probably cannot protect it by copyright. 2. If it is not used in commerce, you won't be able to protect since it is not actually a trademark. You can register an intent to use to obtain priority and temporary protection (assuming others are have not already registered the mark or are using in in commerce),, but that protection will not last if use does not timely follow.