Linked from
The 11 pages that link to Partition of unity, each with the reason it gives.
Open setRelated: Open covers organize the local pieces on which these functions are supported.
Smooth manifoldRelated: Partitions of unity combine local constructions into global smooth objects.
ManifoldRelated: Partitions of unity combine local constructions into global ones on many manifolds.
Open coverRelated: Partitions of unity translate a cover into functions supported in its open sets.
Support (mathematics)Related: Controlled supports let local constructions combine into global ones.