memory

1. Cloud Storage

2. Primary

2.1. Internal

2.1.1. RAM

2.1.1.1. Volatile, Read and Write

2.1.2. ROM

2.1.2.1. Non-Volatile (permanent), Read only

3. Secondary

3.1. Hard Disk

3.1.1. Lot of storage, friend to Ram

3.2. CD

3.2.1. CD-R

3.2.1.1. Recordable- once

3.2.2. CD-RW

3.2.2.1. Erase/Rewrite

3.3. DVD

3.3.1. 2 or 3 times more space than a CD

3.4. Blue Ray Disk

3.4.1. Similar like DVD, but very fast

3.5. Pen drive

3.5.1. USB

3.5.1.1. Flash Drive

3.5.1.1.1. Thumb Drive

3.6. Floppy Disk

3.6.1. Less memory

3.6.1.1. 1.44MB

3.7. SD Card

3.7.1. Mobiles, Camera