It's short for insalata caprese, which means "a salad in the manner of Capri" in Italian. The simple salad usually consists of fresh mozzarella, tomatoes, basil, olive oil, and is said to originate on the island of Capri. It will remind you of the Italian national flag, which is striped green, white and red. In case you're wondering, caprese is pronounced ke PRĀ sē.