NAND

Normally refers to the NAND flash chip used in the phone. This is where all the storage capacity comes from. The capacity of this is 4GB, 8GB, 16GB, 32GB, or 64GB. It has two partitions, the system partition and the user partition. The system partition contains the mini Mac OS X operating system and the native Apple applications. This is mounted read only by /etc/fstab, and jailbreaks mount this as read/write. The user partition contains all user data, including installed applications, music, and movies, and is mounted as read/write.

Starting with the iPod touch 3G, firmware files are stored on NAND flash.