Prototyping is a requirements elicitation technique that involves creating a preliminary version of a system or product to validate and refine the stakeholders' needs. It is an iterative process that helps in discovering requirements by providing a tangible representation of the product that stakeholders can interact with. This interaction allows stakeholders to give immediate feedback, which is then used to refine the prototype in subsequent iterations. Prototyping is particularly useful when stakeholders find it difficult to articulate their needs or when the requirements are not well understood.
References: The use of prototyping as a technique for iteratively validating stakeholder needs is supported by the Business Analysis Body of Knowledge (BABOK) guide, which is a standard for the practice of business analysis123.