1. STORAGE – 3 TIERS
Key Revision Points

2. INTRODUCTION
Anywhere the computer stores data, instructions or programs is storage
This includes memory as it is required for temporary storage
Programs a loaded into RAM when run
Registers in the CPU store memory addresses, instructions, data or results of calculations
There are 3 tiers (levels) of storage

3. PRIMARY
Memory the CPU can access quickly – sometimes called the Immediate Access Store
Fastest type of storage
In speed (and size) order:
Registers
Cache
RAM and ROM
Most primary storage is volatile

4. SECONDARY Where data (programs, user files) are stored when not in use
Much slower read/write times than primary storage
Also called auxiliary storage
On most computers this is the hard drive
Also includes Optical Media, SD Cards, Solid State Drives, USB Flash Drives*
Secondary Storage is non-volatile
NOT USB
NOT CD Drive, DVD Drive, Card Reader

5. TERTIARY Used for long term storage of data – archiving and backup
Magnetic tape is commonly used
Massive capacity but…
Very slow read/write access

6. Textbook
Textbook page 6