Gaussian splatting
A way of storing a 3D scene as a cloud of soft coloured blobs, which renders fast and looks photographic.
Instead of building a scene out of flat triangles like classic 3D graphics, Gaussian splatting fills it with many small fuzzy blobs, each with a position, a colour, a size, and a transparency. Rendered together they reconstruct what a camera would see from any angle. The name comes from the Gaussian, the bell shaped falloff that makes each blob soft at the edges rather than a hard dot.
It became popular from 2023 onwards because it is both fast to render and unusually good at capturing messy real world detail like foliage and reflections, which traditional modelling handles badly. If you have seen an AI reconstruct a room from phone photos and let you fly through it, there is a decent chance splats were involved.