You can call it a kippah (in Hebrew) or a yarmulke (in Yiddish) but a Jew will seldom refer to it as a “skullcap” or a “beanie.” It signifies respect: respect for the One who is greater, or respect for the community in which it is a custom.
For some, it may also be a fashion statement or a small personal billboard on which to express one’s passions.
I wear a little hat when I’m praying or studying. It’s called a kippah, in Hebrew, or a yarmulke, if you prefer Yiddish.
I wear the little hat to cultivate a Jewish virtue, tzniut (tznee-OOT).Tzniut means modesty. The hat is a reminder that I am not a big shot (what big shot would wear a ridiculous hat that looks like a coaster, and that sometimes slides over her left ear?) When I pray and when I study, I am standing before the Holy One. I am not a celebrity. I’m just a fallible little rabbi, wearing a silly little hat.
There is nothing magic about the little hat. It isn’t a mitzvah, a commandment, to wear it, just a custom. Some Jewish men wear them all day, every day. Some Jewish women cover their heads with kippot, some with other kinds of head coverings. But all the head-covering is basically about tzniut, about modesty, and about the custom of the community.
Every person should have two pockets. Each pocket should have a note in it for a time of need. When he feels miserable that person should reach into one pocket to find the words: “The world was created for my sake!” But on a day when he feels high and mighty, he should reach into the other pocket to find the message: “Remember, I am nothing but dust.”
True modesty is balanced somewhere between those two notes.