Quality control (QC) is a process that businesses use to ensure that a product or service adheres to a predefined set of quality standards. It is a part of quality management that focuses on fulfilling quality requirements. QC involves testing units and determining if they are within the specifications for the final product. The purpose of the testing is to determine any needs for corrective actions in the manufacturing process. The extent of QC actions must be determined, for example, the percentage of units to be tested from each lot. The quality control used in a business is highly dependent on the product or industry, and several techniques exist for measuring quality. QC is similar to, but not identical with, quality assurance (QA). While QA refers to the confirmation that specified requirements have been met by a product or service, QC refers to the actual inspection of these elements. QC is an indispensable aspect of various industries, ensuring that products and services adhere to predefined standards. It is critical in verifying the potency and purity of drugs, ensuring they are safe for consumption. QC is also used in the software industry, involving extensive testing of applications and programs to identify bugs and errors before release, guaranteeing a smooth user experience. QC is a fundamental process that enhances customer satisfaction, boosts efficiency, and fosters a reputation for reliability.