Power generation, in this industry, means the machines that turn wind, sunlight and gas into electricity, and the software that watches them. The equipment makers sell these machines to power producers, the companies that own power plants and sell their electricity to the grid.
There are two main families. The first spins a generator. A wind turbine spins it with wind. A gas turbine spins it with burning gas. A standby generator does the same on a small scale, to supply a building when the grid fails. The second family uses sunlight directly. Solar panels turn sunlight into direct current. A solar inverter converts it to the alternating current that the grid uses, and a solar tracker turns the panels through the day to follow the sun. This conversion is explained on the page about AC and DC.
A newer product is AI for nuclear reactor design. It does not make power itself. It helps engineers decide how a reactor should be built.
These machines suit different jobs. Wind and solar need no fuel, so they cost little to run once built, but they produce power only when the wind blows or the sun shines. A gas turbine produces power whenever gas is supplied, and it starts fast. Say that on a May evening a state needs 1,000 MW at 8 pm. Solar panels now give 0 MW because the sun has set. Wind farms give 300 MW because it is breezy. The grid operator asks gas turbines for the remaining 700 MW, if it has no stored power to use.
The maker of a machine earns twice: once when the machine is sold, and again for many years from spare parts and repairs. So most of these machines carry sensors that report to the maker. The maker uses these readings for predictive maintenance, which means repairing a part just before it would fail. See also aftermarket service. The machines also send their output to the grid operator, and rooftop systems are one example of the grid edge.