Basic Guide about Computer Memory And Storage Devices

What is computer memory?

When you heard the computer memory phrase, you should think about the physical device that may save the data and information. Every device which has to execute the program or system needs memory in the primary form and secondary form. Whilst we provide any command to the tool, instruction associated with that program loads in the primary memory and it’s going to execute by using the control processing unit.
The human frame is controlled through the human mind which gives us to command to do any work. Like the human brain-pc memory also stores the facts. It stores the set of instructions to execute the system software properly.

Types of computer memory

In particular, all pc tool comes with 2 kinds of memory.

  1. Primary (most important) memory
  2. Secondary memory
Primary memory

Primary reminiscence is also called the primary memory or main memory. A storage tool that stays inside your instrument that’s called primary storage. It may be rightly retrieved by the CPU manner I/o channels. To manipulate the system software of every technical device, you ought to need the primary memory.
Right here, we have discussed 3 types of main memory. The primary one is RAM, the second one is ROM and the final one is Cache memory.


You can also say that RAM is short-term memory. None of your program documents can be accessed or run without RAM space that is a crucial part of the computer memory. RAM is transient statistics storage on your technical device.
When you power on the pc, the cope with of the practice is loaded into the RAM according to the controller’s command. So, CPU can get the required instruction without delay from the RAM and this technique may be very fast.


The word ROM is a long-term reminiscence. The full form of second primary memory ROM is read-only memory. Because the name indicates we can simplest study it, can’t write on it.
As you all understand your technical device comes with some in-built software. To run that everyone software and application your device wants some preparation that has been saved internal ROM. When you begin your device, some instructions will load in RAM from the ROM and executes the program.
When you may turn off your device all commands are erased from RAM which is loaded before but remains inside the ROM. So, you can access it again whilst you power on your computer, mobile phone, or some tool.

Cache memory

Usually, cache memory is used to reinforce the efficiency of the CPU.
In a few conditions, the CPU uses the same records again and again. So, the CPU first reaches the cache reminiscence and reveals the information which it wishes. If it does not found records or data in the cache memory then the CPU goes into the RAM.
We can say that cache memory is a buffer and it connects the CPU and RAM. Cache memory only stores the regularly requested facts by the CPU. Consequently, cache memory decreases the access time of statistics and makes the fast execution of the machine.
Cache memory is very costly so the normal tool no longer comes with cache reminiscence.



  • Random-access memory
  • More speedy
  • It will erase when power cuts
  • RAM can read data, modify and delete.
  • More expensive
  • CPU direct access the data from RAM.
  • single cheap more storage capacity


  • Read-only memory
  • Less speedy
  • It will not erase during power cuts even when you turn off your device.
  • ROM only read the data
  • Cheaper than the ROM
  • Data loads from ROM to RAM.
  • very less storage capacity
Secondary memory

Primary memory has a limitation of storage capacity. Secondary memory overcomes the difficulty of main. Secondary memory is also called secondary or auxiliary storage devices and external memory.
Interior secondary reminiscence, you may save records in large quantities. You can store statistics in GB to TB inside secondary memory. Roughly, we can say that it could store 64 to 128 times extra storage capacity than the main memory. It’s referred to as a backup or permanent storage device. Even though energy turns off facts will no longer be deleted from the secondary memory.
From the secondary reminiscence, the CPU can’t get entry to records at once. First records loads from secondary memory to number one memory thru the I/O channel and the CPU takes facts from the number one memory.

Types of secondary memory

There are mainly 4 types of secondary storage devices.

  • Magnetic storage devices
  • Optical storage devices
  • Flash storage devices
  • Cloud storage
1. Magnetic storage devices

Many humans don’t recognize the hard disk is a magnetic storage device. It stores the statistics in the magnetized fabric in the binary form and non-volatile form. Inside this type of tool micro electromagnets to be had which generate the magnetic field and we can write/ read data within the devices.
Here, I am giving the call of a few magnetic devices. Jaz disk, Hard drive, Magnetic Tap, Zip disk, Floppy disk. Right here, study extra about a majority of these gadgets.
Due to extra capacity and small size hard drive is extra famous in the marketplace. All different devices you may discover uncommon inside the marketplace due to low capacity and less storage and running potential.

2. Optical storage devices

When you have used a CD drive then you have heard a few sounds of rotating disc whilst you placed it inner medial player or your pc. It makes use of low-power laser beams to read information from the spinning disk. Laser beam converts the data binary to digital.
These days, use of the optical device is decreased because of much less garage capability. In maximum optical devices, we can write simplest as soon as when it’s far production. So, It’s known as a worm ( Write once study many).
I have given a few optical gadgets and information about it. Read in detail about optical garage gadgets.

Nonrecordable (Read-only)
  • CD-ROM (Compact Disc – Read-Only Memory). It sores data up to 800 Mb.
  • DVD-ROM (Digital Versatile Disc – Read-Only Memory). 4.7 Gb data storage capacity.
  • HD-DVD (High-density DVD). It stores up to 15 Gb data.
  • Blue-ray disk. 25 to 50 Gb storage capacity.
Recordable (Read and write)
  • CD-R and DVD-R
  • CD-RW and DVD-RW
  • DVD-RAM (Rewrite the data). 4.7 Gb storage capacity.

Flash memory storage devices

Flash Memory is likewise a non-volatile storage medium that may be readable and rewritable. It knew as EEPROM ( electronically erasable programmable examine-only reminiscence ). It makes use of to shop records electronically in computers and different gadgets like a USB flash drive, MP3 players, digital cameras, and SSD (stable-state force).
There are 2 types of generation utilized in flash memory, NAND and NOR for mapping the records. NOR flash can get right of entry to statistics very rapidly so that it makes use of within the pc or cellular telephone working structures. NAND flash read and write statistics with a high speed so that it uses inside the storage devices like SSD and pen drives.
Permit’s see the name of the flash storage tool. Read in detail.

  • USB flash drive ( Pen drive)
  • Memory card ( Flash memory card)
  • CF ( Compact flash)
  • MMC ( multimedia card)
  • M.2 SSD (M.2 solid-state drive)
  • SD card ( Secure Digital card)
  • SSD
  • XD picture card
  • NVME (Non-Volatile Memory Express)
  • SDHC card (Secure Digital High Capacity card).

Cloud storage

Cloud storage is the choice to store statistics on a far-off server. You may access the data from the cloud storage at any location. Moreover, your records are safer in cloud storage than your laptop because maybe your pc or hard disk can burn but there are only a few adjustments that appear in the cloud storage.
Without permission, absolutely everyone can’t get the right of entry to your data from the cloud so that cloud storage is very secure. Additionally, you may control or edit your information and may permit others for doing the same work.
Nowadays, many businesses provide cloud garage areas for non-public use. To use cloud storage for enterprise purposes you need to pay some money. Google, Adobe, Microsoft, and lots of other organizations provide loose cloud garage as much as 5 to 15 Gb in step with a single account.

Primary memory vs Secondary memory

Primary memory
  • volatile in nature.
  • Internal memory
  • Short term memory
  • Erase after power turn off
  • More costly
  • Less storage capacity ( Mb to Gb )
  • very fast
  • Non-portable
  • CPU can access data from primary memory
  • RAM, ROM, and Cache memory
Secondary memory​
  • non-volatile in nature.
  • External memory or auxiliary memory
  • long term memory
  • Permanent storage
  • Cheaper than primary memory
  • More storage capacity (Gb to Tb)
  • Slow compare to primary memory
  • Portable
  • CPU can’t access data directly from secondary memory
  • Magnetic storage, Optical storage, Flash storage, and Cloud system.

History of the storage devices

These days, we’re using very small storage devices to shops the statistics of size Gb and even Tb. While this storage device become invented in the 18th century, the size of it is very massive as just like the room. Although it shops records of length some Bytes.
We have to thank the technology due to the fact now we will shop Many Gb or Tb records in a small pen drive and we can position it into our pocket. Right here, list of garage devices to be had with the 12 months wherein it become invented. Read in detail.

  • Before 1440 – the only paper
  • 1440 – printing
  • 1750 – punch card
  • 1877 – phonograph
  • 1928 – magnetic tape
  • 1932 – magnetic drum
  • 1949 – magnetic core
  • 1956 – hard drive
  • 1963 – music tap
  • 1971 – floppy disk
  • 1980 – CD
  • 1984 – CD – ROM
  • 1995 – DVD
  • 1996 – CD-RW
  • 1997 – MMC ( multimedia card)
  • 2001 – SD card
  • 2003 – XD picture card
  • 2004 – HD – DVD
  • 2006 – cloud storage

In this technological era, to store a very big size of data many devices and remote servers available. Many big companies have millions of Tb data. So, when time has gone size of storage devices is decreasing and storage capacity is increasing.


From the above guide, you can say that primary memory devices are more expensive and important than secondary storage devices. Nowadays, in the market, you will get a secondary storage device at a very cheap price but it can’t boost the performance of your technical device. Due to the new invention, you can store 1 to 2 TB of data in the small and portable Pen drive.