iTunes

Definition:

iTunes is an application created by Apple. Using iTunes you can listen to music and watch videos both on your computer and on CDs. It also allows you to legally purchase and download digital music, movies, and television episodes as well as transfer music to and from an iPod and subscribe to podcasts.

Here's a word you may not know...

CPU

The Central Processing Unit, or CPU, is often referred to as the brains of the computer. It is the part of the computer that performs all of the operations and decisions to support the computer's various functions.