A "Handler" typically refers to a person or system that manages or controls something, often in a specific context. In the realm of technology, a handler can be a piece of software that processes data or events, ensuring that tasks are executed correctly. For example, in programming, a callback handler manages responses to events like user inputs or system notifications. In the context of animals, a handler is someone who trains or manages animals, particularly in settings like dog shows or service animal training. These individuals are responsible for the care, training, and performance of the animals, ensuring they respond appropriately to commands and behave well in various situations.