This thorough article from Chabad.org provides a comprehensive introduction to the Havdalah ceremony that concludes Shabbat, including an outline of the ritual, an exploration of the deep spiritual meaning behind it, and some technical details and customs about how to perform this ritual at different points in the Jewish calendar according to Orthodox Jewish law. With many internal links, such as to the full step-by-step procedure and text, this is a useful resource for people of all backgrounds.Â