I don't know Jack

I was playing solitaire on the iPod and tried to teach the boys how to play. Here's us discussing the Jack.

Bubba: What is the J for?
Bobcat: Is he the prince?
Bubba: King is the K, queen is the Q. Prince does not start with J. Right?
Me: J is for jack.
Bobcat: Is the prince married to a princess?
Me: Well, a princess can be a wife or a sister. But the jack isn't a prince. I think.
Bubba: The prince's name is Jack?
Me: No, it's not his name. He is a "jack". That's his title. Or his job.
Bobcat: What does a jack do?
Bubba: I think he's like a prince.
Me: I'm really not sure what his job is. I don't know what he does. I'll have to look it up.
Bubba: Oh, so we just call him Jack because we don't really know who he is?
Bobcat: No, he's just A jack! (rolls eyes)
Me: Be nice, Bobcat. We're all a little confused here...
Bubba: So, can we watch you play that other game now with the fireballs?
Bobcat: When I'm a grown up, I'm going to play lots of video games.

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I'm going to go look up the Jack on Wikipedia now.

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Update: According to Wikipedia:
"As early as the mid-1500s the jack was called the knave (meaning a male servant of royalty). The card came to be known as the jack during the middle of the 19th century, when card manufacturers began to label playing cards to indicate their value with 2, 3, 4, 5, 6, 7, 8, 9, 10, J, Q, K, A. The obvious confusion between "Kn" and "K" led to the renaming of the knave, being out-ranked by the king. However, books of card games published in the third quarter of the 19th century evidently still referred to the "knave", and the term with this definition is still recognized in the UK."

There ya go.