U.S. patent law
A method claim is used to define an invention as one or more acts. A method claim defines the invention in terms of what the invention does or how it is done, as opposed to what the invention is structurally. A method claim allows a patent applicant to divorce the function of the invention from the structure of the invention.
A method claim can be identified by the presence of the term “method” or “process” in the preamble of the claim. The terms “method” and “process” are used interchangeably in this type of claim. A method claim is infringed when the acts of the method are performed.