Watts, lumens and lux
Watts describe electrical power. Lumens describe the light output of a source or luminaire as specified. Lux describes how much light reaches a surface. A wattage alone does not tell you whether a space will be well lit.
Colour and visual comfort
Colour temperature describes the warm-to-cool appearance of light. Colour rendering concerns how colours appear. Comfort also depends on distribution, viewing position, mounting and the surrounding surfaces.
Protection and suitability
IP and impact ratings describe particular tested properties. They do not on their own establish resistance to every chemical, cleaning process or specialist environment.
A specification belongs to a variant
Check that the datasheet, light-distribution file, driver, optics and control option refer to the exact product being proposed. Confirm the conditions behind any performance or lifetime figure.