In Jewish practice it is closed with its own ritual, one that names the boundary between holy time and ordinary time.
Havdalah marks a separation
Britannica defines Havdalah as the ceremony concluding the Sabbath and religious festivals. Its blessings praise God for distinguishing the sacred from the ordinary, light from darkness, and the Sabbath from the weekdays.
That is what the word itself means: separation.
The ritual uses wine, spices, and fire
Britannica explains that Havdalah is recited over wine and, on the night after Shabbat, over spices and a braided candle.
These materials matter because the ritual is sensory as well as verbal. The end of sacred time is tasted, smelled, and seen.
It protects the boundary of sacred time
Havdalah matters because Judaism takes transitions seriously. Shabbat is not meant to dissolve into the workweek without acknowledgment.
The ceremony teaches that holiness is real enough to need a boundary and visible enough to require a public act of closing.
Why it still matters
Havdalah still matters because modern life blurs every boundary it can. The ritual insists that sacred rest and ordinary labor are not identical and should not be treated that way.
The shortest accurate answer
Havdalah is the Jewish ceremony that ends Shabbat or a festival, marking the separation between sacred time and the ordinary week through blessings over wine, spices, and flame.