disinfectant are those which kills the microorganism but not their spores.

Disinfection in our labs means reducing the microbial load but not necessarily killing all microorganisms or their spores. As opposed to sterilisation, which kills all the microorganisms and their spores.

A disinfectant kills vegetative cells of pathogenic microbes on inanimate surfaces. Compare to a sterilant that kills vegetative cells and spores of spore forming bacteria on inanimate surfaces and an antiseptic that kills bacteria on animate surfaces.