What does a requirements document specify?

A requirements document serves as a foundational component in the process of database design and software development. It specifies what the stakeholders need from the system, capturing the essential functionalities, services, and constraints that the system must meet. By outlining the specifications for software, applications, or databases, it helps ensure that all parties have a clear understanding of the objectives and deliverables.

This document is instrumental in guiding the development process, as it lays the groundwork for subsequent phases, including design, implementation, and testing. Clearly defined requirements enable developers to create a solution that is aligned with the users' needs, improving overall satisfaction and effectiveness.

The other choices specify aspects related to implementation or design details but do not encompass the overall purpose of a requirements document. For instance, while design layout and performance criteria are important considerations, they stem from the requirements outlined in the document rather than being the document's focus. Similarly, data types used in the schema are determined during the design phase after gathering the initial requirements but are not specified within the requirements document itself. Thus, the answer accurately reflects the broad purpose and importance of a requirements document in the development life cycle.