An asterism in Orion, formed from 3 stars. Not one of the 88 constellations.
Three bright stars in a near-perfect line, spaced almost evenly. Nothing else in the sky looks like it, which is why it is the pattern most people can find first.
Orion's Belt is centred near right ascension 5.6 hours, declination -1°. It straddles the celestial equator, so it is visible from essentially anywhere on Earth at the right time of year.
The International Astronomical Union recognises 88 constellations, and they divide the whole sky between them like countries on a map. Orion's Belt is not one of them — it is a pattern picked out of Orion. That makes it an asterism: a shape people recognise and name, with no official standing whatsoever.
The distinction matters less than it sounds. Asterisms are usually easier to find than the constellations containing them, which is exactly why they survive.
SkyRef can draw Orion's Belt in its real position for wherever you are — switch on the asterism layer and it appears dashed across the constellations it runs through.