In Texas, the Transmission and Delivery Utility (TDU) is the company that delivers electricity from the power grid to homes and businesses nearby. Your local TDU is who you call for power outages and other line and pole related emergencies. There are four main utility providers in Texas:
Oncor: North, West & Central TX
Centerpoint: Houston Metropolitan Area
TNMP: Western & Northern Central TX
AEP Texas: South & West TX
TDU's are not to be confused with Retail Electric Providers in Texas. While the TDU works to distribute electricity in your region, the retail electric companies you can choose as your provider turn your lights on and send you your monthly bill.