What's the difference between a smart light socket and a smart plug?

A smart light socket screws directly into an existing bulb fixture (E26/E27) and adds a smart bulb holder, which is ideal for ceiling fixtures, porch lamps, and enclosed sockets where a plug won't fit. A smart plug controls a plug-in device or string lights at the outlet. Several well-reviewed smart plugs exist, but they don't solve the screw-in fixture use case.