Property is the right to exclude others.
When you say that you own your land or your house, in legal terms this means that you have the right to exclude others from entering them. Similarly, your stuff, known as chattel, is said to be yours because, contrary to what your mother told you as a child, you do not have to share. Because intellectual property is not as easy to identify as your land, house or other stuff, it is sometimes called intangible property. Moreover, since IP rights are the right to exclude others, they are not a right to use your intellectual property freely. For example, you may patent an invention, but you are not free to make, use or sell it if it would infringe someone else's patent.