Storage devices are used to store data and information in a computer. There are two main types: primary and secondary storage. Primary storage includes RAM, ROM, and cache, which can be directly accessed by the CPU. RAM is used as the computer's main memory and comes in DRAM and SRAM varieties. ROM is used to store basic startup instructions and cannot be modified. Cache provides faster access to frequently used data. Secondary storage includes hard disks, which are not directly accessible by the CPU and require transferring data through primary storage. Hard disks are computers' main storage and come in internal and external varieties.

1. Storage
Devices

2. Content

3. What is Storage Device
means?
 A storage device is used in the
computer to store data and
information.
 It provides one of the core functions of
the modern computer.

4. Types of Storage Devices

5. Primary Storage
 Also known as main memory
 Main memory is directly or indirectly
connected to the CPU via a memory
bus.
 Example:
 RAM
 ROM
 Cache

6. RAM(Random Access
Memory)
 Any of the data in RAM can be
accessed just as fast as any of the other
data.
 There are two types of RAM:
 DRAM(Dynamic Random Access Memory)
 SRAM(Static Random Access Memory)

7. Types of RAM
Static RAM Dynamic RAM
• Faster
• More expensive
• More power consumption
• Does not need to be
refreshed.
• Slower
• Less expensive
• Less power consumption
• Need to be refreshed.

8. ROM
 This memory is used as the computer begins to boot up.
 Small program called firmware are often stored in ROM
chips on hardware devices(like BIOS chip),and they
contain instruction the computer can use in performing
some of the most basic operations required to operate
hardware devices.
 ROM memory cannot be easily or quickly overwritten or
modified.

9. Cache
 Cache is a high-speed access area that
can be either a reserved section of
main memory or a storage device.
 Most computers today come with L3
cache or L2 cache, while older
computers included only L1 cache.

10. Secondary Storage
 It is not directly accessible by the CPU.
 Computer usually uses its input/output
channels to access secondary storage
and transfers the desired data using
intermediate area in primary storage.
 Example:
 Hard Disk

11. Hard Disk
 The hard disk is the main, and usually
largest, data storage device in a
computer.
 Hard disk speed is the speed at which
content can be read and written on a
hard disk.
 Disk access time is measured in
milliseconds.

12. Types of Hard Disk
Internal Hard Disk External Hard Disk
Portability No Yes
Price Less expensive More expensive
Speed Fast Slow
Size Big Small

13. Any Questions ?

14. Thank you !!