A deodorant is a substance applied to the body to prevent or mask body odor due to bacterial breakdown of perspiration or vaginal secretions, for example in the armpits, groin, or feet. A subclass of deodorants, called antiperspirants, prevents sweating itself, typically by blocking sweat glands.

Two types of products can help with body odor: Deodorants cover up the smell of body odor, usually with fragrances. Antiperspirants stop or dry up perspiration or sweat. They do this by temporarily blocking the pores where sweat comes from.

Antiperspirants work by blocking the sweat glands to reduce sweating, while fragrances are just added to mask body odour. A deodorant typically contains sweat-absorbing ingredients like aluminium chloride or zinc oxide as well as fragrance. Perfumes, on the other hand, contain higher concentrations of fragrance oils.