✅ Computer Memory Units ✅

   • Computer Memory Units | Bit | Nibble ...  

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✅ What is Cache Memory ✅

   • What is Cache Memory | Meaning | Work...  

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✅ What is RAM and its Types ✅

   • What is RAM and its Types | Static an...  

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✅ What is ROM and its Types ✅

   • What is ROM and its Types | PROM | EP...  

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✅ Difference between RAM and ROM ✅

   • Difference between RAM and ROM | Rand...  

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✅ What is Secondary Memory ✅

   • What is Secondary Memory | Magnetic T...  

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✅ Difference Between Primary Memory and Secondary Memory ✅

   • Difference Between Primary Memory and...  

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00:00 Starting
00:14 Meaning of secondary memory
01:24 Types of secondary memory
02:07 What is Magnetic Tape
03:12 What is Magnetic disk
04:14 What is Hard Disk
05:35 What is Floppy Disk
06:26 What is Optical disk
07:08 What is CD - Compact Disc
08:18 What is DVD - Digital Versatile Disc
09:02 What is Blu-ray
09:37 What is Flash Memory
10:27 What is Pen Drive
11:02 What is SD-Card

1.) Magnetic Tape
Developed in Germany in 1928.
It use a read-write mechanism.
Data read and write speed is slower.
It become more scarce due to the advanced storage devices.


2.) Magnetic disk
A flat disc covered with a magnetic coating to write, rewrite and access data.
Two types of magnetic disks are hard disks and floppy disks.

a.) Hard Disk
It is also called a hard drive.
It stores the operating system, applications, documents, files, pictures and music.
They are less expensive and they can store terabytes of information.
It comes in both variants, internal as well as external.

b.) Floppy Disk
A floppy disk is a square plastic case.
These disks are available in sizes like 8 inches, 5.25 inches, and 3.5 inches.
Due to the other portable storage devices, they are less in use nowadays.

3.) Optical disk
It is an electronic storage medium because it uses low-power laser beams to record and read data.
The data is read while bouncing the laser beam on the surface of the disk.
CD, DVD, Blu-ray all are called optical disks.

a.) CD - Compact Disc





A Compact Disc (CD) is a circular shape device made of polycarbonate plastic.
CD has two types. One is CD-R (compact disc recordable - read but can't write) and the second is CD-RW (compact disc rewritable - read and write).
It can store up to 700MB of data.

b.) DVD - Digital Versatile Disc
The DVD is a digital video disc or digital versatile disc, data storage format invented and developed in 1995 and released in late 1996. Currently, a DVD can hold a maximum of 17.8GB of data.

c.) Blu-ray
It is like the third generation optical disc, after CDs and DVDs, and capable of storing several hours of high-definition video.
The maximum storage capacity of blu ray discs is up to 50GB.

4.) Flash Memory
It was invented in the 1980s by Japanese engineer Masuoka Fujio.
He said that the process of memory-erasing was like a camera’s flash. So he suggested naming this new technology “flash memory".
They are workers of Toshiba Corporation.

a.) Pen Drive
A pen drive comes in 1 GB to up to 2 TB of storage capacities.
It is used to store massive data.
To use a pen drive, we need to plug it into a USB port on a computer.
It is small but has a large storage capacity.

b.) SD-Card
It is known as a Secure Digital Card.
It is used in mobile phones, cameras, music players, etc.
It is available from 1 GB to 1 TB of storage capacity.

Types of Secondary Storage Devices

1.) Sequential -
a.) Magnetic Tape

2.) Direct -
a.) Magnetic Disk ( Hard Disk and Floppy Disk)

b.) Optical Disk (CD, DVD, and Blu-ray)

c.) Flash memory (Micro card and Pen drive)

CD DVD Blu-ray
magnetic disk
magnetic tape
flash memory
pen drive, sd card
hard disk
floppy disk
external hard disk
internal hard disk
optical disk kya hai