Linked from
The 17 pages that link to Radiant intensity, each with the reason it gives.
Solid angleRelated: It measures how emitted power is distributed across directions.
Radiant fluxBroader topic: It resolves total source flux into its directional distribution.
RadianceRelated: It shares radiance’s directional measure but does not divide by source area.
RadiometryBroader topic: It describes directional power when total radiant flux is insufficient.
Spectral radianceCompared with: Unlike spectral radiance, it does not divide by projected area.
SteradianRelated: Its denominator is measured in steradians, linking source power to angular spread.