Ma'anar ƙamus na kalmar "haske" yana nufin adadin hasken da ke fitowa ko kuma ya fito daga saman, wanda aka auna shi da raka'a na ƙarfin haske a kowane yanki. Yana da adadi na zahiri wanda ke bayyana hasken sama ko wani abu a cikin takamaiman alkibla. Ana amfani da haske sosai a fagagen kimiyyar lissafi, na'urorin gani, da kuma daukar hoto don bayyana hasken tushen haske da fahimtar haske na abubuwa.