What is the difference between miniLED, microLED and OLED?
They differ in what produces the light, and that single distinction determines contrast, brightness, burn-in risk and price.
OLED. Each pixel is its own light source, made of organic compounds that emit light when current passes. A black pixel is switched off entirely, giving effectively infinite contrast and perfect blacks. Response times are extremely fast, and panels can be very thin and flexible.
Its limitations: peak brightness lower than the best backlit sets, particularly over large bright areas; burn-in risk from static elements over long periods, substantially mitigated by pixel shifting and refresh routines but not eliminated; and organic materials degrading over time, with blue degrading fastest.
MiniLED. Not a new pixel technology at all — it is a backlight improvement to a conventional LCD. Thousands of very small LEDs sit behind the panel in local dimming zones, brightening and dimming independently. More zones means better contrast.
Its characteristics: very high peak brightness, which makes it strong in bright rooms and for high dynamic range highlights; no burn-in risk in practice; and blooming — a halo around bright objects on dark backgrounds, because a zone is larger than a pixel and cannot dim around a small bright element.
MicroLED. Genuinely self-emissive inorganic LEDs, one per subpixel. It combines OLED's per-pixel control with far higher brightness and no organic degradation — technically the best of both. The obstacle is manufacturing: placing millions of microscopic LEDs accurately remains extremely expensive, so it currently appears in very large modular displays and commercial installations rather than ordinary televisions.
How to choose, practically: a dark room and film watching favours OLED; a bright room favours miniLED; static content for many hours a day — a computer monitor showing fixed interface elements, or a television left on a news channel — favours miniLED; and gaming favours OLED for response time, with modern panels carrying good burn-in protections.
QD-OLED and QLED confuse matters: QLED is a backlit LCD using quantum dots for colour, while QD-OLED is genuinely self-emissive.