Screens pretty much just have two things to worry about: size and resolution. A screen’s size is usually given in inches, and is measured from one corner to its opposite, so a 12” screen is twelve inches from the bottom left to the top right corner. A bigger screen naturally means a bigger, and in turn heavier, laptop, so is usually only a good idea if you don’t intend to be lugging it off to lectures every day – it also makes for a better gaming and video viewing experience as well.
The next thing to consider for your screen is its resolution, which is basically how many pixels it is made up of. As a good reference point, 19200×1080 (commonly referred to just as 1080p) is the resolution of a Blu-ray film, and the standard resolution of most high definition TVs. It is also the most common resolution of widescreen PC monitors, particularly for gaming PCs. For the vast majority of people, 1080p is the perfect resolution. For smaller laptops, however, a lower resolution is a good trade-off for portability and speed. Remember, though, that a bigger screen doesn’t mean the picture will look any better – if the resolution is the same as a smaller screen, then you might notice the pixels more, and edges may start to look jagged.
There are some laptops out there, such as the Chromebook Pixel, which combine a standard screen with a super-high resolution for fantastic picture quality but this comes, as you might expect, at a very high premium, and is totally unnecessary for most users. Though 4K resolutions (displays with a staggering 4096×2160 pixels) are being increasingly talked about with regard to TVs and PC Gaming, anything over 1080p is pretty much pointless in a laptop, and the hardware necessary to manage such high resolutions would be incredibly expensive.