How is reliability defined in the context of software products?

Reliability in the context of software products is defined as the ability of the software to perform its required functions under specified conditions over a designated period. This definition focuses on the consistency and dependability of the software, ensuring that it operates correctly and as expected without failures.

In practical terms, reliability means that a user can trust the software to carry out its intended tasks consistently, whether it is routine operations or handling unexpected scenarios. This aspect is critical, particularly for software that is used in environments where errors can have serious consequences, such as banking, healthcare, or any safety-critical systems.

The other options describe important aspects of software quality but do not encompass the full definition of reliability. For instance, handling multiple users simultaneously relates to performance and scalability, adapting to user requirements pertains to flexibility and maintainability, and maintaining data integrity is about robustness and correctness. Each of these characteristics contributes to overall software quality, but reliability specifically emphasizes the ability to perform required functions without failure over time.