Computer’s Primary and Secondary Storage
Storage Device/Media
Data needs to be stored for later use on storage media. The two types of storage media are:
- Primary storage media
- Secondary storage media
Primary storage media
It is the internal storage area of the machine.
Random Access Memory (RAM)
This is the memory that the computer uses for storing the programs and their data while working on them.
RAM has the following characteristics:
Data within the RAM can be read or modified, i.e. you can either read from the RAM or write onto it. Hence it is called
Random Access Memory (RAM)
ROM (Read Only Memory) –
It is internal permanent storage memory.
ROM contains permanently recorded instructions that are vital for starting the computer.
One set of instruction in ROM is called the ROM-BIOS
All machine-level instructions are stored in the ROM.
Secondary storage media
Compact Disk (CD ROM)
Floppy Disk
Cartridge Tape
Magneto-Optical Disk
USB drive / Pen Drive
Memory Stick
Hard Disk
Permanent Storage Memory
Hard Disk: – Data store permanently
Size may be 20GB , 40GB, 80GB,160GB, 320GB, 500GB, 1TB.
About Memory Size
1 Nibble = 4 bits 1Byte = 8 bits
1 Kilobyte (KB) = 1024 Bytes 1 Megabyte (MB) = 1024 KB
1 Gigabyte (GB) = 1024 MB 1 Terabyte (TB) = 1024 GB
1 Petabyte (PB) = 1024 TB 1 Exabyte (EB) = 1024 PB
1 Zettabyte = 1024 EB
