Pin/tech bindings are the go-to choice for backcountry touring and ski mountaineering. They use two small pins at the toe that clamp into matching fittings on your boot, plus a heel piece that locks down for descending. The big advantage is weight — they're significantly lighter than other touring options, which makes a real difference on long uphill climbs.
The tradeoff is downhill performance. Pin bindings have less elastic travel than alpine bindings, so they don't absorb shocks as well and can release prematurely in aggressive terrain. They also don't transmit power to the ski as efficiently. If you love charging hard on descents, this is worth considering.
One more thing: pin bindings require boots with tech-compatible toe and heel fittings (ISO 9523 soles). Standard alpine boots won't work. If you already own alpine boots and only tour occasionally, a hybrid binding might be the better fit.