Protection starts with knowing what must be protected and who may act. Detection notices a possible object; tracking follows it; classification estimates what it is; verification checks the evidence. A decision process determines a proportionate response, followed by assessment of the result. A sensor alert is not proof of a hostile drone.
Radar, radio-frequency sensing and optical or thermal sensors provide different kinds of information. Command software combines observations. Organisational measures and physical protection can accompany technical systems. Electronic or physical intervention is a separate capability and requires an appropriate legal and operational basis; detection equipment alone does not confer that authority.
Vendor claims should be checked against a defined test situation, false alarms, environmental limits and independent observations. A claimed detection radius, a demonstration and a verified operational result are different kinds of evidence. This directory is an explanation of roles, not a product endorsement.