A regulator is an entity or device that controls or manages a process, ensuring it operates within specific limits. In various fields, such as finance, energy, and healthcare, regulators set rules and standards to maintain order and protect public interests. For example, a financial regulator oversees banks and financial institutions to ensure they follow laws and regulations. In engineering, a regulator can refer to a device that maintains a constant output, such as a pressure regulator that keeps gas or liquid pressure stable. This helps prevent equipment damage and ensures safety in systems like gas pipelines or water supply networks.