Your answer is good. To add to it, the large "transmission" grid usually covers extremely high voltage lines: 115 kV, 138kV, 230kV, 345kV, 500kV, 765kV and up.

Your answer is good. To add to it, the large "transmission" grid usually covers extremely high voltage lines: 115 kV, 138kV, 230kV, 345kV, 500kV, 765kV and up. It is managed by both utilities and RTO/ISO organizations that manage large sections like air-traffic controllers. Distribution is typically below ~100kV and is really more in the 11kV range and managed by the utilities almost exclusively. Building new transmission lines can be ~$1 billion projects.