What is a rough or unfinished drawing made to assist in the creation of a finished product?

The term that best describes a rough or unfinished drawing made to assist in the creation of a finished product is "sketch." A sketch is often used by artists and designers as a preliminary representation of an idea or concept. It serves as a visual aid that allows the creator to experiment with composition, shapes, and forms without needing to commit to a final version. Sketches are typically informal, quick, and not concerned with precision, focusing instead on the basic contours and ideas to communicate thoughts effectively.

In contrast, a draft usually represents a more developed version of a document or plan but is still subject to revisions. A prototype refers to an early sample or model intended to test a concept or process, while a model is a three-dimensional representation of an object, often used to visualize ideas or designs in more detail. While all these terms relate to the creative process, a sketch specifically emphasizes the initial stages of artistic or design development, making it the most appropriate choice in this context.