Its electric, and usually the smaller leafier plants rather than roots or huge rambling heirloom tomatoes. Room humidity can be too low, and heat ranges too high so the systems can fight the hvac unless its in a tent or something. I have grow lights and heat mats but this winter its saving full grown peppers to set out next spring. And herbs. Maybe some patio tomatoes. I do not see a water setup for that little bit.
That would be a fun name for flood hydroponics, Ducks' .
Maybe the practitioners call it that but, to those of us who know next to nothing, they refer to one type of equipment as a flood table. It's set up to drain the flood, you see . That seemed like a sensible way of dealing with the practice, to me.
The water, with its added plant nutrients, is held in a reservoir. A pump on a timer periodically lifts the water onto the table where it floods the plant roots. Then, the water drains back into the reservoir. And, that is about all I know.
The commercial greenhouse where I worked had a misting table. It was probably similar but was used for propagating from cuttings. Water was also on a clock but it was just a pipe from the irrigation system that came through sprinklers that sprayed it as a mist above the cuttings. They rooted in perlite and the water, what very little there was, just drained away in the soil beneath the metal table.
The table was surrounded by heavy plastic to hold in the mist and maintain humidity. Since there were no nutrients available to the plants, they couldn't remain on the table for long but they would soon develop roots and could be moved off of it to more conventional growing.
That might be defined as a very limited hydroponic system.