Screen size is measured diagonally in inches, while resolution measures the number of pixels that make up the display. But a bigger monitor doesn't necessarily mean greater resolution; the 24-inch Eizo has a higher resolution than the 27-inch NEC, for example.
A more useful measure of the 'crispness' of a display is pixel density, measured in pixels per inch (ppi). The NEC is 82ppi, the Eizo 94ppi, while Samsung and Dell weigh in at 109ppi.
Monitors increasingly offer more than just a simple display for your computer, with built-in speakers, USB hubs, card readers and multiple inputs, such as HDMI, for use with a variety of devices.
While true-to-life colour reproduction is very important in image editing, you may need to compromise to get all the features you want within budget.
LED backlighting allows thinner displays, while IPS (or Samsung's PLS) allows for greater viewing angles.
We'd always recommend using a digital interface like DVI or HDMI, but it depends on what your computer has. Do you want to plug in multiple devices? Make sure your new monitor has the same input as your computer has output!
Several of these displays enable you to swivel the monitor from side to side and turn the screen 90 degrees into portrait mode.
Most monitors are now capable of Full HD resolution (1920x1080) but more and more can do higher resolutions - many here are capable of 2560x1440, for example.
With so many devices plugged into our computers these days, a USB hub really is something you'll wonder how you lived without.
So many monitors - including several of these - are just plain ugly. Also see what people are saying about the button controls and menu system. Ensure it is usable.