How does instrumentation differ from orchestration in music?

In the context of music, the terms instrumentation and orchestration are closely related and often used interchangeably to describe the arrangement or composition of music for instruments. However, they can be distinguished by their scope and focus:12

• Instrumentation refers broadly to the selection and use of instruments for a particular purpose or ensemble. It encompasses the specific choice of instruments—whether for a symphony orchestra, a rock band, or a string quartet—and how those instruments are applied to achieve a desired sound.234
• Orchestration is a specialized subset of instrumentation, specifically focused on the arrangement or composition of music for an orchestra. It involves the technical and artistic process of assigning musical lines to specific instruments to create balance, texture, and color.135

While instrumentation addresses the general "what" (the selection of instruments), orchestration focuses on the "how" (the detailed management of those instruments within an orchestral setting to realize a composer's vision).35