Distribution (differential geometry)
In differential geometry, a discipline within mathematics, a distribution on a manifold M {\displaystyle M} is an assignment x ↦ Δ x ⊆ T x M {\displaystyle x\mapsto \Delta _{x}\subseteq T_{x}M} of vector subspaces satisfying certain properties. In the most common situations, a distribution is asked to be a vector subbundle of the tangent bundle T M {\displaystyle TM} .
Source: Wikipedia — Distribution (differential geometry) (CC BY-SA 4.0)