What Is External Storage? [The Only Guide You'll Ever Need]

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Aditya Rayaprolu
Written by
Aditya Rayaprolu

Updated · Sep 06, 2023

Aditya Rayaprolu
Technology Architect | McKinsey & Company | Joined February 2023 | LinkedIn
Aditya Rayaprolu

Aditya is an Azure DevOps and Infrastructure Virtualization Architect with experience in automation,... | See full bio

Terry Stancheva
Edited by
Terry Stancheva


Terry Stancheva
UI Expert and SEO Ninja | Joined October 2021 | LinkedIn
Terry Stancheva

Terry spends her time researching all things digital — from marketing through online business crea... | See full bio

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External storage is non-volatile data storage outside a computer's internal components, often called an external drive. These drives are frequently connected to computers through USB, eSATA, or FireWire. It can be removed and accessed elsewhere. 

Examples of external storage are floppy disks and optical discs, compact flash drives (USB flash drives and memory cards), portable storage devices (external solid-state drives and enclosure hard disk drives), and network-attached storage.

In this article, you will learn more about the basics of external drives, their types, pros and cons, and their significance in the digital world.

Key Takeaways

🔑 A compact disc, or CD, is a flat, round optical storage medium invented by James Russell. 

🔑 If you use DVD, no unwanted data alteration can occur during the transfer because it is not permitted to re-write data to disc.

🔑 External drives are available in various sizes and interfaces, including USB, e-SATA, and Firewire.

🔑 An HDD resembles an airtight case containing one or more platters and an arm with several heads.

🔑 Currently, three storage systems are available: external, internal, and cloud.

External Drives: Unraveling the Basics and Beyond

All data storage not housed in a computer's primary storage or memory is stored on an external storage device. Its equipment might be temporary or permanent, detachable or non-removable, and wired or wireless in how it connects to a network.

External storage allows users to segregate data from a computer's primary storage and memory at a reasonable cost. It expands storage capacity without requiring the system to be opened.

In 1953, IBM recognized the immediate application for a "Random Access File" with a high degree of rapid random access at a low cost. The engineers at IBM's San Jose, California, laboratory invented the hard disk drive after considering technologies such as: 

  • Wire matrices
  • Rod arrays
  • Drums
  • Drum arrays 

The minicomputer age ended when PCs were released in the 1980s. As a result, the industry sought more capacity manufacturers such as IBM, DEC, and Hewlett-Packard to continue to produce external hard drives.

Apart from their history, external storage devices have evolved. Find out the different types of external drives, their pros and cons, and how to find the proper external storage. 

Types of External Drives: Finding the Right Solution for Your Data

As technology progresses, various kinds of external storage emerge. This ranges from CDs, DVDs, external hard drives, flash drives, and memory cards.

You can delve more into each external drive. Continue reading!

Compact Disk (CD)

A compact disc, abbreviated as CD, is a flat, round optical storage medium invented by James Russell. On August 17, 1982, the first CD was manufactured at a Philips factory in Germany. The image depicts the bottom of a standard compact disc, the side the disc player reads. A label on the opposite side of the disc indicates what is on it.Pros and Cons of Using CDs


Compact discs, although an old technology, still have advantages. Here they are:

  1. Larger Capacity: Compact discs have a greater storage capacity than cassettes and floppy disks. A 3.5-inch floppy disk can only hold 800 KB to 2.8 MB of data, but a CD can hold 700 MB.
  2. Rewritable Formats: Rewritable formats such as CD-R and CD-RW are available. The commercial availability of these mediums makes storage accessible to the general public.
  3. High Audio Quality: CDs have a broader dynamic range and lower noise levels than vinyl and cassette recordings, resulting in better and more accurate sound reproduction.

Along with their advantages, CDs also have disadvantages because they have remained obsolete due to emerging technologies in data storage. Some of its cons are: 

  1. Issues with Durability: A CD is fragile because it is easily scratched if not treated carefully. It might deform and become unusable when exposed to severe heat and humidity.
  2. Obsolete: Another issue with CDs is that they have become obsolete due to the availability of superior storage mediums and digital downloads. 
  3. Older Technology: CDs have older read-and-write mechanism technology based on a 780nm wavelength. Blu-ray Discs use a 405nm wavelength read and write technology.

Digital Versatile Disc (DVD) 

A digital versatile disc, or digital video disc, is a disc that can contain far more data than a typical compact disc. DVDs are commonly used to store and view movies and other data.

The first DVD-ROM drives that used these discs were sold in 1997.

Pros and Cons of Using DVDs


DVDs are still present in today’s technology because of some of their advantages in data storage. Here are some of its pros. 

  1. Cheap: The raw materials used to make DVDs are inexpensive. In addition, DVDs are a low-cost choice for data storage compared to other storage methods.
  2. Offline data transfer: DVDs are used for movie distribution, software distribution, driver distribution, and so on. When internet distribution is unavailable or problematic, this is a superior option.
  3. Data Protection: When transferring data using DVD-R, data is protected, and it is difficult for unwanted data alteration to occur during the transfer because DVD-R is not permitted to re-write data to disc.


DVDs also have disadvantages, mainly when data requires high storage capacity. Some of its cons are. 

  1. Low durability: The DVD's soft surface is easily scratched, causing it to stop performing correctly and causing data loss.
  2. Device compatibility: DVDs are incompatible with some PCs, laptops, tablets, smartphones, televisions, etc. 
  3. Capacity Restrictions: Typically, DVDs range from 4 GB to 12 GB. It is unavailable in different capacity sizes to meet the user's needs.

External Hard Drives

The simplest and most affordable way to add more storage, whether for media storage or to back up your computer, is with external hard drives. 

This external storage device requires only a USB cable attached to your computer, making it convenient to use and carry with a laptop in multiple locations.

Desktop external drives are available in various sizes and interfaces, including USB, e-SATA, and Firewire.

Most external hard drives are typically SATA-based, but you can pay more for an SSD (Solid State Drive) model for increased speed.

Pros and Cons of Using External Hard Drives


External hard drives make storing data more convenient and easily accessible. Here are some of the pros of external hard drives.

  1. Offline access to data: External hard drives are much smaller and more portable. You will not need to be connected to the internet to access your data. Keeping your sensitive data offline reduces any online assault.
  2. Portability: Some of these hard drives are small enough to fit in your hand, making them ideal for storing in a backpack or purse. The portability allows you to carry data that is likely three to four times the size of your usual laptop.
  3. Transfer Speed: Most external hard drives offer fast transfer speeds when transmitting large amounts of data. You can expect an average transfer rate of 150 megabytes per second. 

As with any other data storage device, external hard drives could be better but have their share of cons. Here are some of them. 

  1. Fragile: If you do not have a casing to protect it from bumps and shakes, you may accidentally ruin your hard drive. 
  2. Overheating: Most external hard drives are designed to accommodate cooling fans. However, more than these cooling fans may be required under excessive heat, as your hard drive may heat to 45-50 degrees Celsius when in operation.
  3. Easy to steal: Small, removable devices are easy to steal and conceal, and once taken, they can be exploited by whoever stole them. 

👍Helpful Article:

If you want to find out what SSD you have, this article will give you easy techniques.

For external drives, there are two types. One is the Hard Disk Drive (HDD), and the other is the Solid-State Drive (SSD).

Learn more about HDDs and SSDs. Continue reading!



It uses mechanical spinning disks and a moving read/write head to access data.

Uses memory chips.



More storage capacity.

Less storage capacity.


More expensive.

Best for storing large amounts of data like documents, movies, and photos.

Best for storing apps and operating systems.


A hard disk drive (HDD) resembles an airtight case containing one or more platters and an arm with several heads (transducers). Data is stored on a platter covered with a magnetic substance and is written and read using heads that move over the platter as it spins.

An HDD is a low-cost solution for storing large amounts of data you will not need daily. 


SSDs, or Solid-State Drives, have no moving parts. They store data on flash memory chips, similar to  USB thumb drives. An SSD and a memory chip have a controller chip that locates the requested data.

An SSD is better if you intend to use an external data storage device for photo or video editing and require quick file access. 

Flash Drive 

Unlike an optical or standard hard disk, a flash drive is a compact, ultra-portable storage device with no moving parts. This type of external drive is sometimes called a pen, thumb drive, or jump drive. 

Flash drives connect to computers and other devices through a built-in USB Type-A or USB-C socket, resulting in a USB device and cable hybrid.

Pros and Cons of Using Flash Drives


Flash drive portability is one of their advantages, but it doesn’t stop there. Other advantages of flash drives include the following: 

  1. Speed: USB drives have relatively fast transfer rates because they do not require an internet connection. However, various factors influence speed, including the USB version, hardware bus, and USB controller device.
  2. Physical Dimensions: USB drives are compact and light, making them highly portable. They may fit inside pockets and bags without any difficulty. It is an excellent alternative to hard drives and tablets, which require a lot of space. 
  3. Capacity: USB drives initially offered a limited storage capacity range. Until now, USB devices with up to 2TB capacities were available. As a result, users are relieved of the burden of carrying external hardware in cases with huge storage capacities. 

Flash drives also have their fair share of limitations and disadvantages. Here are some of its cons. 

  1. Vulnerable to viruses: If one of the PCs becomes infected with malware, it can quickly transfer it to a flash drive because it is not malware-free. This may render the files illegible, rendering them useless.
  2. Manufacture Quality: Some manufacturers create low-quality USB drives at a lower cost. Printed circuit boards are always integrated with a metal tip using soldering procedures. The stress point can be weakened if the parts are not correctly soldered. 
  3. Short Lifespan: USB drives do not have an infinite lifespan. The number of read and write cycles is only around 100,000. After this time, the USB drive will most likely fail. They are not suitable for booting operating systems or executing programs. 

Memory Cards

A memory card is a storage device used to save media and data files. It is a persistent and non-volatile storage medium for data and files from the associated device. Memory cards are widely used in portable devices like cameras and phones.

It is primarily used in mobile phones, cameras, and other portable and handheld devices as primary and portable flash memory. PC Cards (PCMCIA) were the forerunners of current memory cards when they were commercially introduced. 

Besides offering non-volatile media storage, a memory card employs solid-state media technology, which reduces the likelihood of mechanical difficulties such as those seen in traditional hard drives.

Pros and Cons of Using Memory Cards


Memory cards are one of the smallest data storage devices there are. It may be small, but it has several pros for data storage. Here are some of them.

  1. Compact and Lightweight: They are small and may be in tight quarters. They are 
  2. Device Compatibility. Mobile phones, digital cameras, PCs, laptops, and tablets all use them.
  3. Non-volatile Memory. Even without electricity, they do not lose or delete data or information.

Although memory cards are the most recent development in data storage, they also have cons that will make you think twice about buying them. Here are a few of them.

  1. Slow Transfer Rate: The transfer speed of a memory card is slower than that of internal memory and RAM (Random Access Memory).
  2. Durability: Memory cards are sensitive, delicate, and easily destroyed.
  3. Sensitive to Electrostatic sources. Exposure to things that create static electricity should be avoided when working with memory cards since they might cause damage or corruption.

🎉Fun Fact: 

TransFlash, or TF, is essentially the old moniker for what is now known as a microSD card. It was created by Motorola and SanDisk and released in 2005.

Now that you have learned about the various types of external drives, it is also essential for you to know the differences between external storage, internal storage, and cloud storage. 

Comparing External, Internal, and Cloud Storage

There are three storage systems: external, internal, and cloud. You must choose these three options when you want to store, secure, and protect your data.  

Before you decide what data storage system to use for your data, find the similarities and differences below.


External Drive

Internal Drive

Cloud Storage


Data security is quite strong. Hackers can only access your hard drive if it is connected to your computer. 

Encryption is available but might slow the computer process.

To protect your data before it leaves your devices, secure cloud solutions now have unbreakable encryptions so that even if a hacker had your data, they would be unable to access it.


You can get terabytes of storage for at least $100.

More expensive than an external drive.

You need to pay for a monthly subscription.

Sync Technology

Automatic backup software can be used. However, your external drive must be permanently attached for this to work.

No sync technology is needed unless manually backed up or used with backup software.

It has sync technology that automatically uploads new or modified files to your storage space. There is no need to worry if your files have been backed up.

Universal Access

Many wires are involved when transferring files from one device to another. It’s not a backup you can easily set up on the go.

You need an external storage device to transfer files.

You only need an internet connection to transfer files to and from the cloud.

Now that you have learned the differences between the three storage devices, you must also know how to choose the right external drive. 

Smart Considerations for Choosing the Right External Drive


Storage space is arguably the most essential factor when purchasing an external drive. Acquiring a high-speed gadget with encryption and remote access is only worthwhile if it can hold some of your data.

Speed and Performance

Transfer speed is also highly significant. If you frequently transfer data to a large drive, you don't want to wait forever for the transfer to complete.


Mobility is vital to keeping your drive with you when out and about. It should be lightweight and compact enough to fit in a pocket or backpack and be easily accessible. You also want one that does not require an extra power cable.

Durability and Form

Current external drives frequently feature rigid enclosures to protect them from damage. But it is wise to choose an SSD because it has moving parts. An SSD is more resistant to drop harm than a standard hard drive and, thus, far more durable.

Price and Budget

External hard disk drives are slightly more expensive than internal hard disk drives, and your budget will help you decide whether to go with a desktop-bound solution or a more portable one.

Suppose you have already chosen the best external drive for you. In that case, it is also essential that you know how to take care of and maintain your external drive to preserve your data.

Vital Tips in External Drive Maintenance: Keeping Your Data Safe and Sound

Taking care of your external drive is important because it stores your data. To make sure this data is secured and preserved. You must observe proper methods to maintain your external drive.

Here are some tips for maintaining your external drive.

  • Safely eject drives from your computer.
  • Keep your drives free from dust and physical damage.
  • Monitor the drive's health and performance.
  • Safeguard data with encryption.
  • Keep your external hard drive in an excellent location with appropriate temperatures for its model.
  • Use a surge protector because it will assist in limiting or eliminating damage to your hard drive and computer in the event of an unexpected power surge.


External storage offers more space, portability, and the ability to share data between devices. It is available in various formats, including CDs, DVDs, external hard drives, flash drives, and memory cards, each with advantages and disadvantages. 

External drives are also very different from internal drives and cloud storage, each with perks and cons.

After learning all these facts, you should know how to care for your external drive to protect and secure your data.


Can you use an SD card as external storage for my PC?

Yes, you can use an SD card as external storage by using a memory card adapter and connecting it to your PC.

Is it OK to always keep the external hard drive plugged in?

It is usually safe to leave a portable external hard disk plugged in and active 24/7 but ensure proper ventilation to avoid overheating.

How long can data be stored on an external hard drive?

Data can be stored on an external drive for about 3 to 5 years or until your external drive stops working. 

Can a hard drive last ten years?

Solid-state drives also have a longer lifespan—up to ten years. Hard disk drives survive between 3-5 years.


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