Smart meters are subject to the same safety regulations and testing as other in-home technological devices, including wi-fi hubs, baby monitors and mobile phones.
They measure the flow of electricity or gas and send this information to energy suppliers.
Short bursts of radio waves send readings remotely from gas and electricity meters into a communications hub which is then sent to an Ofgem-regulated body called the Data and Communications Company (DCC), and from there onto your energy provider.
If you live central or south of the UK the info is sent via a data network provided by Telefonica (better known as O2). If you live in the north of the UK, the network is run by a company called Arqiva.
SMETS2 meters also provide two-way communications. This means your energy supplier can send product and payment details to the meter when you want to change your product or payment terms. This is also how SMETS2 remain 'smart' when you switch energy suppliers.
Some media have reported that smart meters are bad for your health due to emitting radiation.
However, smart meters operate at a broadcast frequency of 2.4 GHz - this is the same frequency as a cordless landline phone, baby monitor, or garage opener - and is lower than mobile phones and wifi equipment.
Public Health England (PHE) has been studying the effects of exposure from smart meters and says exposure to radio waves from smart meters is well below the guidelines set by the International Commission on Non-Ionizing Radiation Protection (ICNIRP).
The study showed that exposure to radio waves from smart meters is likely to be much lower than that from everyday devices such as mobile phones and wi-fi equipment, and one million times less than international health guidelines.
This is because smart meters are only actually transmitting low power signal radio signals for short periods of time, typically 0.1 per cent to 1 per cent of the time, and because of the distance the meters are located from the body.