Minkowski sum
The set of all sums a+b of points from two bodies — the foundation of how modern collision algorithms reason about overlap.
The sum A ⊕ B is what you get by sweeping one shape around the boundary of the other. What matters for collision is the difference A ⊖ B, that is A ⊕ (−B): the two bodies intersect exactly when that difference contains the origin. The whole question "do they collide?" collapses into "does the origin lie inside this one shape?"
Named after Hermann Minkowski (1864–1909). For convex polygons the sum is itself convex and can be built in O(n+m) by merging the edges sorted by angle. The same idea underpins motion planning (obstacles inflated into configuration space, or C-space) and is the engine inside both GJK and EPA.