A registered trademark is like the Nike Swoosh or the Logo a business uses to represent itself. This prevents (should) chinese knockoffs of look alike goods.
A copywrite applies to literature or software etc.
Here's an example:
CocoCola - their logo is a registered trademark.
The recipe of their soda is a trade secret. Should they decide to publish it, they would have a copywrite on the recipe. This would prevent others from duplicating the document that comprises the recipe (a cook book if yoyu will). This would not prevent anybody from following the recipe to make Coke for personal use or profit.
If they applied for a patent on the recipe (the combination of ingredients to make soda and probably the method) and it was granted, this would have given them a monopoly on the product for 17 - 20 years.
Go to
United States Patent and Trademark Office for further clarification on the difference between copywrites, trademarks, and patents.