So my daughter asked me what a prototype was. It was a little tricky to come up with a quick explanation since prototypes can range from a block of wood carried in your pocket (I’m looking at you Jeff Hawkins) to a nearly minimum viable product version of an app.
After giving it some thought I decided that in kid language, prototypes are kind of lame samples of your idea, used to see if your idea makes sense/will work or not.
If it works you invest the cash and time into the concept to fully develop it. If it doesn’t work, no harm done because you didn’t waste an exorbitant amount of time or money on it.