It's common in computer graphics and user interface programming. You want to move your character around a 2D grid, but you don't want either of its x and y coor

It's common in computer graphics and user interface programming. You want to move your character around a 2D grid, but you don't want either of its x and y coordinates to ever move outside the bounds of the 2D grid. Or you want a web page with an article section that is 50% of the browser width, but never narrower than 300px and never wider than 800px.