An energy supplier is a company that acquires electricity, renewable energy or natural gas supplies from the wholesale market and sells it retail to homes and businesses. An energy supplier is not your local utility, it does not own or operate the distribution and transmission systems that deliver energy to homes and businesses.
An energy supplier simply purchases and supplies energy, which is then delivered to your home by your local utility. The utility still operates the local distribution wires and pipes which carry electricity and natural gas through its territory and to homes or businesses.