What is a smart meter and how does it work?
A smart meter measures your gas or electricity use, just like a traditional meter. But unlike a traditional meter, a smart meter sends its readings to your supplier automatically. Once your smart meters are installed, you won't need to read your gas and electricity meters any more.
https://help.bulb.co.uk/hc/en-us/articles/360005132971-What-is-a-smart-meter-and-how-does-it-work-