The law provides for different rights, depending on the subject matter concerned, the evolution of the law through courts and legislative bodies, and practical implications. Some people think that a patent or a trademark gives the owner a right to use the subject matter covered by the patent or trademark. They don’t. Patent rights are exclusive rights: they give the owner the right to exclude others from making, using, and selling the content claimed in the patent.
The world of patents is a complex playing field of evolving rights. New patents are being introduced all the time, and expired patents are constantly falling out. In this complex field, the right to practice an invention and the right to keep others from practicing it are forever changing. Inventors must understand the difference between the right to use and the right to exclude. In what often seems a paradoxical situation to inventors, having a patent does not mean you can make and use your invention. It only means you can prevent others from making and using your invention. Inventors may question the value of a patent if this is true, but that exclusive right is the value. It is the value in controlling the marketplace by keeping others out. But when the Patent Office grants you a patent, it is merely saying that you now have an right to exclude others from practicing your invention; it does not make a judgment as to whether you can practice it yourself.
You may wonder in what situations you would have a patent on your invention but not be able to use the invention. Just as you, as a patent holder, can prevent others from practicing your invention, other patent holders can prevent you from practicing theirs. And if your invention borders too closely to theirs, they can prevent you from practicing yours. Further, practicing your invention may be impossible if it involves something that breaks the law. This is it, essentially. Because what you have created may be prohibited by law or by someone else’s patent rights, you can be prevented from using your invention.
Here’s a very rough analogy. Are keys to a car equivalent to a right to use the car? Not really. Just because a person is in possession of keys to a car doesn’t mean they have the right to use that car. Their license may have been revoked. The car may be impounded. It might be inside someone’s garage. The person may be under age 16. Some other third party has decided whether they have the right to use the car. But, as long as they hold the keys, they can keep other people from driving that car. The keys confer, roughly, not the right to use the car (because that ability is determined by outside forces), but the right to keep others from using the car.