NAND

Normally refers to the NAND flash chip used in the iPhone, iPad and iPod Touch. This is where all the storage capacity comes from. The capacity of this is 4GB, 8GB, 16GB, 32GB, 64GB. It has two partitions, the system partition and the user partition. The system partition contains the iOS operating system and the native Apple applications. This is mounted read only. The user partition contains all user data, including installed applications, music, and movies, and is mounted as read/write. The jailbreak modifies the "fstab" file in /etc and enables read and write on all 2 partitions.