i) Luminous intensity: This is defined as the luminous flux emitted into a solid angle of space in a specific direction. Its unit is the candela.
The luminous flux per unit solid angle (per steradian), as measured in a given direction relative to a light source. Its unit is the candela.
ii) Luminous Flux: The luminous flux is the total energy radiated by the light source in all direction. The unit of luminous flux is lumen (lm)