Toddler balance bikes

Toddler balance bikes or run bikes was a term that I was unfamiliar with up until two years ago. But then my grandson came along and his cycling parents insisted he get a balance bike. Before my grandson could walk steadily he was off on his toddler balance bike! It was the strangest thing I had ever seen. Toddler bikes used to consist of three wheels or training wheels. Not any more I guess.