In software testing, what is a 'defect'?

A defect in software testing refers to a discrepancy between the expected outcome and the actual outcome when the software is executed. This variance indicates that the software is not performing as intended, which can lead to functionality issues or user dissatisfaction. Identifying defects is crucial for ensuring software quality, as they must be addressed before the software is released to users.

The concept of a defect encompasses any flaws or inaccuracies in the software that prevent it from working as designed or specified. This definition aligns directly with the expectations that testing aims to meet, making it a foundational aspect of quality assurance practices. By identifying and classifying these defects, testers can help developers understand where the software fails to meet its requirements.

Other choices do not properly define a defect in the context of software testing. A feature enhancing the user experience does not qualify as a defect; rather, it's a positive attribute of software. Documentation errors during development might impact communication, but they don't inherently describe the software's performance. Lastly, a performance issue under load, while potentially indicative of a defect, is too specific and does not capture the breadth of what a defect can be in software testing.