OLED (Organic Light Emitting Diode) displays use individual pixels that emit their own light. This allows for true blacks because pixels can completely turn off, resulting in higher contrast ratios and more vibrant colors. OLED screens are also generally thinner and more power-efficient when displaying darker content.
LCD (Liquid Crystal Display), on the other hand, relies on a backlight that shines through liquid crystals to produce images. Because the backlight is always on, blacks are not as deep as on OLED panels. However, LCDs are often more affordable and can sometimes achieve high brightness levels, making them practical for budget and mid-range devices.