There are several considerations when you plan to purchase a monitor.
Monitor sizes are the dominant feature. Larger monitors are more expensive. Monitors are measured diagonally, though the length isnt exactly the correct. It is almost always a little shorter in real life than the length shown.
Resolution is the number of pixels displayed. This is normally shown as the number of pixels wide and the number of pixels tall the screen displays. The larger the numbers, the sharper the image displayed on the screen. Normally, a monitor will be able to display a range of resolutions with more pixels resulting in a slower refresh rate.
Another big concern is LCD or CRT. LCD refers to Liquid Crystal Displays, and these are flat screens. CRT refers to Cathode Ray Tubes, and these are the classic television shaped monitors. LCD monitors produce less eyestrain typically, and have no distortion since every pixel is the same size and shape. This isnt true for the CRT monitor, due to the shape of the glass screen. LCD monitors are flat, and thus take less space on the desktop. They last longer and consume less electricity. CRT monitors are able to...