The idea–expression distinction or idea–expression dichotomy is a
legal doctrine
A legal doctrine is a framework, set of rules, procedural steps, or test, often established through precedent in the common law, through which judgments can be determined in a given legal case. A doctrine comes about when a judge makes a ruling ...
in the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
that limits the scope of
copyright
A copyright is a type of intellectual property that gives its owner the exclusive right to copy, distribute, adapt, display, and perform a creative work, usually for a limited time. The creative work may be in a literary, artistic, educatio ...
protection by differentiating an
idea
In common usage and in philosophy, ideas are the results of thought. Also in philosophy, ideas can also be mental representational images of some object. Many philosophers have considered ideas to be a fundamental ontological category of bei ...
from the expression or manifestation of that idea.
Unlike
patent
A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...
s, which may confer