What intelligent design proposes
Intelligent design, often shortened to ID, argues that some features of living things are best explained by the activity of an intelligent cause rather than by undirected natural processes alone. Its proponents commonly point to biological structures they consider highly complex or difficult to explain through gradual change.
The movement is distinct from every form of religious creationism, although some religious advocates have supported it because its conclusions can be interpreted as compatible with belief in a creator. The identity or nature of the proposed designer is generally left unspecified in the argument itself.
How the scientific discussion differs
Evolutionary biology explains biological diversity through mechanisms including inherited variation, natural selection, genetic drift and common ancestry. These mechanisms are assessed through observations, experiments, comparative anatomy, genetics, geology and other independent lines of evidence.
Most relevant scientific institutions regard evolution as the central framework for explaining the history and diversification of life. Intelligent design advocates challenge aspects of that framework or argue that some features require a design explanation. The central disagreement concerns what counts as a testable explanation and what evidence could distinguish design from natural processes.
Religion and origins
Religious traditions contain varied accounts of creation, purpose and humanity's place in nature. Some believers read sacred creation narratives literally; others understand them symbolically, theologically or through interpretations that accept an ancient Earth and biological evolution. Intelligent design should therefore not be treated as synonymous with religion as a whole.