Shabbat begins on Friday at sunset and ends on Saturday evening after nightfall (when the sun has completely set).
How do we “bring in Shabbat”? By kindling Shabbat candles!
“Jewish women and girls (or men, when there are no women present) light Shabbat candles 18 minutes before sunset on Friday afternoon and on the eve of Jewish holidays… Single girls and women light one candle, and married women light (at least) two candles.”