claim (patent)

In a patent or patent application, the claims define, in technical terms, the extent, i.e. the scope, of the protection conferred by a patent, or the protection sought in a patent application. In other words, the purpose of the claims is to define which subject-matter is protected by the patent (or sought to be protected by the patent application). This is termed the "notice function" of a patent claim--to warn others of what they must not do if they are to avoid infringement liability. The claims are of the utmost importance both during prosecution and litigation alike.