Visual Novels are like regular novels but packaged as a game. They tend to include music, backgrounds and character sprites.
They are also long, their length is more comparable to Books than to Games.
Whether VNs are 'video games’ or their own thing entirely is fiercely debated. I, in all my magnificence, consider them to be their own thing. While some VNs have gameplay, making them more like Games, others do not.
So really, it depends. Some VNs are VNs and Games and others are just VNs.