What are use cases primarily used for in software development?

Use cases serve as a tool to define the specific interactions between users (or other systems) and the software system being developed. They focus on the functional requirements of a system from the end user's perspective, illustrating how users will engage with the application to achieve specific goals. This abstraction helps clarify the requirements and expected behaviors of a system by describing various scenarios of interaction.

By outlining these interactions, use cases provide a framework for both developers and stakeholders, enabling them to understand how the system should perform under different circumstances. This focus on user interaction and functionality makes use cases essential in guiding system design, ensuring that the software aligns with user needs and requirements effectively.