Gallium nitride (GaN) instead of classic silicon sounds like niche knowledge, but it has a very practical effect: the semiconductors generate noticeably less heat loss at the same output. That allows for smaller components — and therefore more compact chargers that fit in any jacket pocket.
For you as a customer, that means: a 65-watt GaN charger is often barely bigger than a classic 20-watt adapter from a few years ago, yet can charge a laptop, tablet and smartphone at the same time.
Our buying tip: pay attention to total output when using several ports at once — it is often lower than the maximum per-port output advertised on the box.