indexed family
collection of objects, each associated with an index from some index set
filtration
indexed set of subobjects
natural transformation
transformation between two functors studied in category theory
Schwarz lantern
pathological example devised by Hermann Schwarz to demonstrate the difficulty of defining smooth surface area
stochastic process
mathematical object usually defined as a collection of random variables
family of sets
collection of some of the subsets of a set; collection of any sets whatsoever
GM High Value engine
engine family from General Motors
parametric family
family of objects whose definitions depend on a set of parameters