“The Veldt” is a short story that belongs to the genres of speculative fiction and science fiction. Speculative fiction is a category that includes all works of fiction set outside the real world (such as horror, fantasy, etc.). Science fiction is a specific category within speculative fiction that focuses on depicting imagined worlds with significant technological advancement.
The primary science fiction element in “The Veldt” is the Hadleys' high-tech Happylife Home, which takes care of every single domestic task for the family, such as cooking them food, tying their shoes, and brushing their teeth. The science fiction thrust of the story comes across in the following description of George and Lydia walking through their Happylife Home, triggering various mechanisms in the process:
They walked down the hall of their soundproofed, Happy-life Home, which had cost them thirty thousand dollars installed, this house which clothed and fed and rocked them to sleep and played and sang and was good to them. Their approach sensitized a switch somewhere and the nursery light flicked on when they came within ten feet of it. Similarly, behind them, in the halls, lights went on and off as they left them behind, with a soft automaticity.
Bradbury describes the sorts of high-tech features that were unimaginable when he published the story in 1950 (some of which have since come to be): full soundproofing, automatic lights, and mechanics that allow the house to clothe, feed, rock, and sing to its residents.
While readers may at first be compelled by the impressive technology of the house, this story essentially serves as a warning to readers who, in 1950, were just getting used to a certain type of consumer culture. By having the Happylife Home turn on the Hadleys at the end (with virtual reality lions in the children’s nursery becoming materially real and killing George and Lydia), Bradbury warns readers to resist the creature comforts that technology may bring.