A card used to identify a person. An ID card can be a driver's license, a passport, or any other card that has that sort of information.
Cards you can use for identification can have your name, age/ birthdate, address, height, hair color, eye color, a picture, and some helpful information for emergancies (ie phone #, car you drive, etc.)
ID cards are used for things like getting into clubs, proving that your old enough to drink, etc.
1. Jenna went to a club, the bouncer needed to see her ID card since she looked younger than 21, even though she was already 24.
2. Addie was going on a trip to Japan, when she got to the airport she needed to show them an ID card to make sure she was who she claimed to be. So she showed them her passport as a form of ID.
3. Brigid, a 13 yr old, asked for a Strawberry Daiquiri. The waiter thought she was older than 13, he actually thought she was anywhere from 16-25 yrs old, and that she wanted an alcoholic drink, so he asked her for ID. Then Brigid said, "I don't have an ID card, I'm 13!"
The waiter said, "Sorry, I thought you were between the ages of 16 and 25!"
(Example 3 is a true story)