Reliability refers to the consistency and dependability of a system, product, or individual. It indicates how well something performs its intended function over time without failure. For example, a reliable car is one that starts every time and requires minimal repairs, ensuring that it can be counted on for transportation. In research, reliability is crucial for ensuring that results are trustworthy. It involves using methods that produce stable and consistent outcomes when repeated under similar conditions. For instance, a reliable survey will yield similar results if administered to the same group at different times, reflecting the true opinions of the participants.