Shabbat is the seventh-day rest that the Hebrew Bible grounds in two distinct reasons: in Exodus it recalls God's rest after creation, and in Deuteronomy it recalls the deliverance from Egypt, so that rest is at once a memory of creation and a claim about freedom. It runs from sunset on Friday to nightfall on Saturday, opened by the lighting of two candles and the blessing over wine (kiddush) and closed by the havdalah ceremony of wine, spices and a braided flame.
What gives the day its character is that its holiness is expressed through restraint. The rabbinic tradition defines rest not as inactivity but as abstention from thirty-nine categories of creative work (melakhah) derived from the labours of building the desert Tabernacle, kindling fire, writing, carrying in public, and the rest. The effect is a deliberately constructed enclosure of time in which the ordinary work of shaping the world is set down. Observance ranges widely, from full halakhic keeping to a candle-lighting and a family meal, but the shape of a day made by stopping is common to all of it.