What drive is external memory?

External memory refers to storage devices that can be attached to a computer via USB, FireWire, Thunderbolt, or other connection types. Some common examples of external memory drives include external hard drives, USB flash drives, memory card readers, and optical drives.

External Hard Drives

External hard drives are one of the most popular and widely used forms of external memory. An external hard drive is simply a standard internal hard drive enclosed in a portable external case that connects to the computer through a USB, Firewire, eSATA, or Thunderbolt connection. This allows you to add significant amounts of storage capacity to your computer easily.

External hard drives come in a variety of storage capacities, typically ranging from 500GB to 4TB or more for desktop models. Portable and pocket-sized external hard drives that do not require a separate power supply generally have lower storage capacities ranging from 500GB to 2TB.

The connection interface used by the external enclosure determines how fast data can be transferred to and from the drive. USB 2.0 offers speeds up to 480Mbps, USB 3.0 is significantly faster at 5Gbps, Thunderbolt can reach speeds up to 10Gbps, and eSATA averages speeds around 3Gbps.

Benefits of using an external hard drive include:

  • Adding more storage capacity to your computer system
  • Providing a portable backup solution that can be moved between computers
  • Allowing fast data transfers for large files like photos, video, and other media
  • Protecting important data as a backup in case of system failure

Popular uses for external hard drives include:

  • Backing up your computer’s internal hard drive
  • Storing and transferring large media files like photos, video, and music
  • Expanding the available storage space on low-capacity laptops and tablets
  • Saving project files from work when moving between home and office computers

Top external hard drive manufacturers include Seagate, Western Digital, Toshiba, Buffalo, LaCie, Samsung, and G-Technology.

USB Flash Drives

USB flash drives, also known as thumb drives or jump drives, are small solid state memory devices that plug directly into a computer’s USB port. They consist of flash memory chips mounted on a small printed circuit board enclosed in a plastic, metal, or rubber case. USB flash drives were first introduced in 2000, with capacities starting at 8MB. Current models can store up to 2TB, with typical capacities between 4GB to 256GB.

USB flash drives connect to computers and other devices via a built-in USB connector. No cables or additional power sources are required, allowing them to be easily used on the go. They are often used to transfer files between computers, back up important documents, physically transfer software programs, and store media files.

Advantages of USB flash drives include:

  • Small size and lightweight portability
  • No power supply or cables needed
  • Wide compatibility across many devices
  • Fast transfer speeds (with USB 3.0/3.1 up to 150MB/s read and 70MB/s write)
  • Reusable – can be erased and rewritten hundreds of thousands of times

USB flash drives are commonly used to:

  • Transfer files between computers and devices
  • Store and transport documents, presentations, photos, videos, etc.
  • Back up personal data
  • Run portable software applications
  • Store and play music files

Leading USB flash drive manufacturers include SanDisk, Kingston, Corsair, Lexar, PNY, Samsung, and Transcend.

Memory Card Readers

Memory card readers are devices that allow you to read and write data to and from various types of memory cards typically used for photo and video cameras. They provide a simple bridge between your camera’s removable storage and computer. Most card readers connect via USB, though some may have Thunderbolt, FireWire, or other connections.

There are a wide variety of memory card formats, including:

  • SD (Secure Digital) – The most widely used format
  • Micro SD – A smaller variant of SD commonly used in phones and tablets
  • CompactFlash (CF)
  • Memory Stick – Sony proprietary format
  • xD-Picture – Used primarily in older digital cameras

The type of card reader you need depends on what memory card format you use in your devices. Many card readers support multiple formats to provide wider compatibility. For example, a typical SD/MicroSD reader would allow you to access both full-size SD cards as well as MicroSD.

Benefits of using a memory card reader include:

  • Provides quick and easy access to photos stored on memory cards
  • Allows transferring images to a computer without cables
  • Faster transfer speeds than connecting the camera directly
  • Portable – card readers are small and require no external power

Memory card readers are most commonly used to:

  • Transfer photos from a digital camera to your computer
  • View and back up photos without a camera
  • Manage files stored on memory cards
  • Transfer videos from action cams like GoPro
  • Extract data from memory cards to back up

Top memory card reader manufacturers include SanDisk, Anker, Transcend, Kingston, and IOGEAR.

Optical Disc Drives

Optical disc drives allow you to access data stored on CDs, DVDs, and Blu-ray discs. This includes both read-only formats like those used for movies and music, as well as writeable formats for burning data. Optical drives were once a standard component built into most desktop computers, but have become far less common today as online media streaming and downloads have reduced the need for physical discs.

There are a few types of optical drives:

  • CD Drives – Read CDs and write to CD-R and CD-RW discs
  • DVD Drives – Read and write DVDs; play commercial DVD movies
  • Blu-ray Drives – Read Blu-ray discs and play commercial Blu-ray movies
  • Combo Drives – Handle multiple disc types, like CDs and DVDs
  • Burners – Can write or “burn” data to writable CD/DVD/Blu-ray discs

External optical drives connect via USB and offer similar capabilities as internal drives, without taking up space inside your computer case. They allow access to optical media for machines like laptops that lack internal drives.

Uses for external optical disc drives include:

  • Reading data from old CDs or DVDs
  • Accessing software or listening to music stored on disc
  • Playing movie DVDs or Blu-rays
  • Importing photos from CDs/DVDs
  • Burning data for backup purposes to writable media

Leading brands include ASUS, LG, Samsung, Pioneer, and HP.

Other Types of External Memory

In addition to the most common options covered above, there are some other types of external memory devices worth mentioning:

  • External SSDs – External solid state drives offer extremely fast data transfer speeds and rugged durability. But they are considerably more expensive than hard drives.
  • RAID enclosures – Allow multiple hard drives to be combined together in RAID configurations for increased capacity, speed, or redundancy.
  • Network-attached storage (NAS) – Networked devices that allow central data storage and backup for multiple users over WiFi or Ethernet.
  • External Blu-ray burners – Write-once external optical drives capable of burning 25GB to 128GB on BD-R and BD-RE Blu-ray media.

Choosing an External Memory Solution

Determining the best type of external memory device for your needs depends on several factors:

  • Intended use – Are you primarily looking to expand storage capacity, back up important files, transfer media content, or something else?
  • Portability needs – If you’ll be transporting it frequently, smaller and lighter options like flash drives make sense.
  • Storage capacity requirements – Larger external hard drives are ideal for expanding storage or backups. Flash drives are better for transfering smaller files.
  • Speed and performance – External SSDs and drives with faster interfaces provide quicker access and transfer times.
  • Security – Make sure the device offers adequate data protection for your use case.
  • Compatibility – Check that the external memory solution works with your OS and hardware ports.
  • Budget – Less expensive options include external hard drives and USB flash drives. Premium solid state and RAID setups cost much more.

Taking the time to consider these factors will help you select your ideal external memory drive, flash drive, or card reader.


External memory devices provide a versatile way to add storage capacity, back up data, transfer files between computers, access optical media content, and more. The most popular options include external hard drives, USB flash drives, memory card readers, and optical disc drives. But specialty products like external SSDs, RAID enclosures, and NAS devices offer additional capabilities for more advanced needs.

Choosing the right external memory solution comes down to factors like intended use, portability requirements, capacity needs, speed, compatibility, security, and budget. By weighing these considerations, you can select the perfect external drive, flash drive, or card reader to suit your individual needs.