There are essentially four types of intellectual property: patent, copyright, trademark, and trade secret.
Registering a trademark protects your good name. A registered trademark associates a particular product that you produce with you as the producer and enables the buyer of the product to know the source and quality of the goods or services that they are selecting in the marketplace. As long as a trademark is properly maintained after you finish the process of registering a trademark, a trademark can last perpetually. A good example of an ancient trademark is the name Du Pont, which goes back to the period shortly after the revolutionary war. The Colt firearms trademark goes back to around the time of the civil war. Registering a trademark helps you protect yourself from having another person confuse the public into believing that they are doing business with you.
Patents are different from registering a trademark in that patents protect your exclusive right to make the things or perform the processes that are your business. Patents exist for a fixed term (which we’ll oversimplify by calling it 20 years, though it is more complex than that and requires some detailed calculations for each specific patent). A patent helps you protect yourself from having some knock-off artist manufacture goods or provide services identical to the ones that you have developed.
Copyright is different from registering a trademark in that copyright protects a particular expression fixed in a tangible medium. Copyright prevents people from reproducing your ideas as they are expressed in print or recording or other tangible form. There may be some overlap in trademark cases where a trademark is a drawing and the re-use of the drawing by a rip-off artist also creates unauthorized use of a registered trademark.
Trade secrets are the things that you don’t tell other people, whether those are your customer list or your secret formula for blueberry pie. Registering a trademark, applying for a patent, or registering a copyright all involve very public conduct. Trade secrets are about protecting yourself from a competitor hiring an employee and learning the things that you don’t tell anyone.