When I first started describing the game I was playing to a friend of mine unfamiliar with the term 'visual novel,' he responded with, "Oh, like a dating sim but without the porn?"
Well, yes. But for those of us less fluent with teenage-male-oriented computer games from Japan than my teenage, male, frequently video- and computer-game playing friend, visual novels are more like a shiny, illustrated Choose Your Own Adventure novel.
Exploring the different options takes you through the story, with the things you look at and the people you interact with popping up in front of you in still frames that change every time you click over to the next line or instance. It's an interesting experience to play, and an interesting medium in which to tell a story and explore a world.