
It´s called a yarmulke (pronounced “yamaka”) in the Yiddish language, and a kippa in Hebrew.
Traditionally the yarmulke was only worn by men, women covered their heads completely using scarves, hats, or wigs. In modern times the push for equality between the sexes in Judaism has led some women to wear yarmulkes. Some Jews only wear yarmulkes while praying, making blessings, or studying Jewish religious texts. More traditional Jews wear yarmulkes the entire day, making sure not to walk more than four cubits, especially outside, without a head covering.
The etymology of yarmulke is unclear. Some linguists eg Max Vasmer, maintain that the Yiddish word is derived (via Ukrainian or Polish) from the Turkic ya?murluk, meaning ‘rainwear’. Other linguists eg Herbert Zeiden, regard this hypothesis as untenable but still believe a Turkic origin is likely, suggesting that the first part of the word may come from yarim, a Turkic adjective meaning ´half´, while the second part may come from qap, a Turkic word for ´cap´, ´shell´, ´enclosure´, or ´container´.
Traditionally, yarmulke is considered to have originated from the Aramaic phrase “yarei mei-elokah” (“in awe of the Lord”), in keeping with the principle that the yarmulke is supposed to reflect someone´s fear of heaven. Or perhaps, “yira malkah” (“fear of the King”).
Kippah is the Hebrew word for dome.
The source for wearing a yarmulke is found in the Talmud. In tractate Shabbat 156b it states: “Cover your head in order that the fear of heaven may be upon you. As well, in tractate Kiddushin 32a it states Rabbi Huna the son of Rabbi Joshua never walked 4 cubits (2 meters) with his head uncovered. He explained: “Because the Divine Presence (Shekhina) is always over my head.”
While there is a minority opinion that wearing a yarmulke is a Torah commandment, most halakhic decisors agree that it is merely a custom, though one that has taken on the force of law. This is codified in the Shulkhan Arukh Orach Chayim 2:6.
Reasons given for wearing a kippah today include:
* recognition that God is above us,
* acceptance of the 613 mitzvot (commandments),
* identification with the Jewish people.
Some have a custom of wearing two head coverings, typically a yarmulke and a hat on top, for Kabbalistic reasons; the two coverings correspond to two levels of intellect, or two levels in the fear of God.