So what's the difference?

Now may be the time for your walls to shine, sort of. Satin, low-lustre and eggshell finishes all have a sheen that is between semigloss and flat paints. Satin and low-lustre paints have a slightly higher sheen than eggshell finishes. Paints in this category are warmer and provide a greater appearance of depth than flat paints. They also resist stains better than flat paints. Consider using these paints for kitchen, dining room, bathrooms, or any area that's typically a place where family and friends tend to gather.