What is "melaveh malkah"

Melaveh Malkah (also, Melave Malka or Melava Malka) (, lit. "Escorting the Queen") is the name of a meal that, as per halakha, is customarily held by Jews after their Sabbath ( Shabbat), in other words, on Saturday evening. The intent of the meal is to figuratively escort the "Sabbath Queen" (the traditional metaphor for Shabbat in Jewish liturgy) on her way out via singing and eating, as one would escort a monarch upon his departure from a city. This meal is alternatively called "the fourth meal."