Smart plugs and sockets use Wi-Fi networks in the home to enable someone to control electrical appliances using an app on their smart device eg a smart phone, tablet device or smart speaker.
A smart plug is an adaptor that sits between the normal plug and the mains power socket. It receives the on / off signal via an app on your smart device, enabling you to control electrical appliances such as lamps, food blenders and smoothie makers, kettles, fans, music and sensory lights. As well as turning them on and off you can also set timers so that they switch on and off at certain times of the day and night, or, in the case of lights, dim to create a more relaxed environment. You can also turn them on when you are out and about, e.g. if you are away and want to make it look like there is someone at home.
Smart sockets work in the same way as the smart plug but they are wired into the standard mains power cabling within the house.