Aperture grille monitors generally allow more electrons to pass through making for sharper and brighter displays. They are also generally more expensive than Shadow mask screens. Refresh Rate - How often the screen is redrawn each second. At 75Hz the screen is redrawn 75 times. Low refresh rates, common in inexpensive and older monitors, cause a perceptible flicker and can lead to eye strain and headaches.
Different resolutions have different refresh rates.
Higher values are better here. The small dots of light that make up the images you see on screen. Get out a magnifying glass and take a peek at your screen. Dot Pitch - The space between pixels. A smaller dot pitch means smaller pixels which translates to finer detail and sharper images.