What is detection?

Detection, in its broadest sense, refers to the process of discovering the presence of something, whether it's an object, a substance, an event, or a change in state. The methods employed for detection vary widely depending on what is being detected, but generally involve using sensors, instruments, or algorithms to identify specific signatures or patterns. Common applications include: detecting diseases using medical imaging; detecting security threats via intrusion detection systems; detecting objects in images or videos using computer vision; and detecting pollutants in the environment using chemical sensors.