Probably, at least if you aim to work professionally in any visual creative field, be it graphic design, photo editing or videography. Some of more expensive monitors that are specifically designed for creative professionals come with their own monitor calibrator tools included. However, in most cases, you'll need to buy a monitor calibrator separately to enable you to calibrate your screen. Some downloadable tools claim to be able to do this too, but they can't actually 'see' your screen like the best monitor calibrators. Failing to calibrate your screen can result in work that looks very different when you see it on another screen or printed out. This can be because your monitor had poor colour accuracy to begin with, because output varies over time or because of the impact of ambient light.