From Proto-Slavic *světъ, related to *světiti ("to shine"). Cognate with Old Church Slavonic světъ and Lithuanian šviẽsti ("to shine"). The same root gave rise to the adjective светлый (svetlyy, "bright/light") and the verb светить (svetit', "to shine").

Свет carries rich cultural weight in Russian. The phrase "на краю света" (na krayu sveta) means "at the edge of the world / in the middle of nowhere," showing the dual meaning of light and world. In folk tradition and Orthodox culture, light (свет) is a powerful symbol of goodness and divinity — churches are lit with candles and described as filled with "Божественный свет" (divine light). The endearment "свет очей моих" ("light of my eyes") is a poetic way to call someone beloved. Be careful not to confuse свет with цвет (tsvet, "colour") — a common error for beginners.