Does AirDrop need Wi-Fi?

Does AirDrop really require Wi-Fi to function properly? I've heard some people say it works over Bluetooth, so what's the truth behind this? Is Wi-Fi a necessity, or can it operate without it in certain scenarios? I'm curious to know if there are any limitations or restrictions when it comes to using AirDrop without Wi-Fi. Can you clarify this for me? It would be helpful to understand the technical details behind its operation, especially when it comes to file transfers and device compatibility.