Rollerblades are ice-skates that have rollers instead of blades on the bottom. Roller-skates have four wheels on each foot consisting of two pairs, one in front and one at the rear, whereas rollerblades have three or four wheels in a straight line on each foot. So why are they called blades? The wheels are not as sharp as a knife blade
but they do resemble ice-skates. I guess that is why they call them roller blades.
If I wanted to, I could go on and on, but it is getting late and I want to get this posted. Feel free to add your own comments and have a great day, you hear?