Linked from
The 21 pages that link to Sampling theorem, each with the reason it gives.
Signal processingRelated: It sets the sampling rate needed to preserve a signal's information.
Dirac combRelated: Multiplication by a comb models uniform sampling and exposes spectral replicas.
White noiseRelated: It sets conditions for representing band-limited white noise digitally.
SamplingRelated: It sets the minimum sampling rate needed to preserve a signal's highest frequency.