Energy network operators manage and maintain the wires, pipes and other infrastructure which delivers electricity and gas to your home, business and community. They are private companies which are regulated by Ofgem and employ around 45,000 people in the UK and Ireland. They are represented by their industry body, Energy Networks Association (that's us).
Their job is to keep energy flowing to your home or business safely and reliably. They operate a Priority Services Register which can help support you if there's a power cut or other energy emergency, and they are the company to contact if you have energy infrastructure on your land.