Don't forget that gratuitousness does not change the state of things. Inversely, what you render as available on the Internet is protected in the same manner and others may not copy without your authorization. Copyright, year, the name of your business. All other use is expressly prohibited. Obviously, when you have a business, it must be possible to find you, in other words that you are intelligently located.
All addresses have three parts.
The center section indentifies you in a unique manner, and with the last part, forms the domain name. All large businesses have one. Trademarks identify a product or service and allow for an association to be made between the trademark and a business. They are often registered with the Trademark office of the various countries. If I were to say to you CocaCola, you would know right away what it means and who sells it.