What Is an ISO File, and How Do You Use It?

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What Is an ISO File, and How Do You Use It?

Key Points

  • ISO files are storage files that represent an exact copy of a disk image and are used to copy or store data from CDs and DVDs.
  • ISO files are commonly used for creating backups of optical disks and distributing large programs and operating systems.
  • Mounting an ISO file requires a virtual disk drive, and burning an ISO file to a disk requires an optical drive.
  • Alternatives to ISO files include RAR/ZIP files, BIN/CUE files, and IMG files.
  • To create an ISO file, you can use utilities like WinCDEmu for Windows or Disk Utility for macOS.
  • ISO files are different from DMG files, as DMG files are only compatible with macOS devices.

ISO files are storage files representing an exact copy of a disk image. You can use these files to copy or store data from CDs and DVDs. ISO files are unique from general disk data in that they can copy boot data needed to run specific programs, like operating systems. However, this may cause additional dependencies that make them unusable over time. Let’s examine these files.

What Is an ISO File?

An ISO file is an uncompressed file representing an exact copy of the data from a disk image based on the ISO-9660 standard, from where it takes its name. This file type is the same one we use for storing data on optical media disks like CDs and DVDs.

ISO files are massive since they store all the data from the disk, including filesystem information like boot code, directory structures, and file attributes. Thus, storing them generally requires allocating some space ahead of time.

What Do We Use ISO Files For?

iso file
ISO files create an exact image archive of the data stored on a disk.

We use ISO files to create backups of optical disks. Their primary use is for distributing large programs and operating systems, as they allow you to consolidate all the system files and registries into one convenient package.

Downloadable operating systems like Windows and Linux distributions typically use ISO files to allow people to access the operating systems, which can be especially handy when moving from an older system to a new one; you can make a copy of your old operating system and transfer it over to the new machine in its entirety.

Mounting an ISO File

You have to mount ISO files to use them. In typical usage, the optical drive would mount the ISO file. However, disk drives are becoming less and less common in computers; many computer cases no longer even allow you to install an optical drive.

However, when using a digital ISO with no accompanying disk, you need to mount the file to replicate the function of the optical drive. You can’t access the information stored within without mounting the file, unless you extract and utilize it that way.

You’ll need to use a virtual disk drive to mount an ISO file. Windows users can use WinCDEmu, and macOS users can use Disk Mounter Utility — which comes pre-installed on all macOS devices by default. You can access these programs by right-clicking on the file you want to mount and clicking “Open With,” then selecting the program you need.

Of course, you could also burn the ISO to a disk and use your disk drive if you have one. This method is perhaps a bit more unwieldy, but no less effective. The two most challenging parts about burning an ISO file to a disk are finding a disk big enough for your file and having an optical drive in this day and age. However, if you happen to have the materials required, you can absolutely access your ISO file the old-fashioned way.

How to Burn an ISO File to a Disk

Burning an ISO file to a disk is pretty easy if you have an optical drive. You can use an internal or external optical drive for this task; the only difference you’ll see from the two is the individual specifications of the drives.

To start, put a blank disk in the optical drive. The computer will read the disk and mount it to the drive. On most computers, this is the D: drive. However, with more computers having multiple storage disks, your CD might also be in the E: or F: drives.

Right-click the ISO file you want to burn to the disk and select “Burn.” After you choose that, you must select the disk you want to burn it to. As we mentioned, this is going to be the D: drive disk on many computers, but it may be E: or F: if you have a newer computer with multiple storage drives.

The computer will begin burning the disk once you’ve indicated a file and drive to burn it to. Once the disk drive pops open, the computer has finished burning the disk. So, you can use it to mount the ISO on other computers with optical drives.

How to Extract an ISO File

Another way you can use ISO files is to extract them. Essentially, an ISO is a container file for all the filesystems and registries that make up the program or operating system. In that sense, it’s much like a massive RAR file that you can mount on the disk drive. However, we use RARs to compress multiple unrelated files, while ISOs are for installing software or operating systems.

Using most file extraction programs, you can extract the files in an ISO file. Windows’ extraction program works just fine for extracting ISO files. Simply right-click the ISO file you want and select “Extract” to start up the extraction utility.

macOS users can do the same thing with the Archive Utility with macOS devices. Control-click on the file you want to extract and select “Open With.” Then, select the Archive Utility to extract the files.

How to Use an Extracted ISO

iso file
Most computers today don’t have optical drives. So, you’ll have to mount or extract your ISO file virtually to use it.

It’s best to extract your ISO file into a unique folder. We designed ISO files to transport huge amounts of data. So, there will be a lot of different files that the program needs to find to run. Having all the files in one place, separate from others, just makes for a cleaner overall system appearance.

Once you’ve extracted the files in your ISO, you actually need to use the ISO to install your program. You must manually start the installation program since you didn’t mount the disk. This task is relatively easy; you’ll just want to navigate to the location of the files on your disk, which is why you should put all the files in one discrete place.

Once you’ve found the files in the storage disk, you’ll want to locate the installer, if there is one, or the program if it’s a full-fledged program that runs off the disk, like old CD-ROM games. Run the installer or program to open it. Essentially, this is what mounting the ISO to a disk drive does. So, you’re just manually performing the function of the disk drive.

Advantages of ISO Files

The main advantage of ISO files is that they create a complete archive image of the information on a physical disk. Typically, when you copy data from a CD to a virtual disk, the image of the files is incomplete. You’ll lose stuff like header and filesystem information.

ISO files solve this issue by copying the data in totality. Since ISO images are complete and include header and filesystem information, they’re the preferred method of transferring data stored initially on a CD.

These files are also excellent for transferring large programs with the accessibility of virtual disks. Using ISO files, you can share operating systems and programs between machines using complete image archives. Since most operating systems today come with a virtual mounting system, you won’t even need to use physical CDs like you would have in the past.

ISO files also allow you to access older programs and utilities distributed by CD. By mounting the ISO file into a virtual drive, you can fool your computer into acting as if you’ve inserted the CD. Thus, you can access the old program even if you don’t have an optical drive.

Disadvantages of ISO Files

Some notable disadvantages of ISO files make them unideal for specific use cases. Firstly, you can’t edit ISO files. Once you package an ISO file, that’s it. You can’t change or add files. Thus, you typically use this file type when you don’t need to repack or edit the files.

Programs and operating systems can be perfectly functional in a previous iteration and updated after they’ve been installed. Thus, ISO files are excellent for transferring these types of programs. However, if you need to edit or change information within the archive regularly, ISO files are wholly unusable. 

You’ll have to completely repack the archive whenever you want to edit the file. Thus, you’ll have to keep all the original files in the archive in pristine condition on the off-chance that you might have to repackage it. In cases where you’d need to edit the archive regularly, you’d be better off using a RAR file. After all, they’re similar to ISOs but provide crucial access to archive editing.

Additionally, you’ll need to mount the ISO whenever you want to access the data. You could extract the ISO to your computer. However, that defeats the ISO’s purpose since you’ll have all the archive data stored on your computer outside of the archive after that.

ISO files are also highly susceptible to file errors. Any corruption in the file leaves the entire file useless and inaccessible. Since you’ll most likely be storing it virtually, file corruption is much more likely than if kept on a physical disk.

While most hard drive errors will be more devastating than a small amount of unrecoverable data, leaving your data in a format that becomes entirely inaccessible should anything go wrong with the data isn’t a good idea. It’s also just faster to use a different file type.

As we’ve mentioned, you’ll need to mount the disk whenever you want to use the files stored in your ISO archive. While this is a relatively simple and quick process, it’s still significantly slower than opening up a RAR file.

Alternatives to ISO

If you need to make an archive of many files, there are several options besides ISO files. However, which one you use will depend on your specific use case. Let’s examine those.


RAR and ZIP files are similar to ISOs in that they store a collection of files in one convenient place. However, RAR and ZIP files are compressed, while ISO files do not use compression. Additionally, you can edit RAR and ZIP files, and add additional data to the archive. We recommend using a RAR or ZIP file if you need to create a collection of unrelated files and compress them to a smaller file size.


BIN and CUE files are also similar to ISO files in that they create an archive of many files. However, BIN and CUE files are raw copies of the disk, including copy protection, error correction, track list, and multi-track data. BIN/CUE files are suitable for making copies of CDs, including audio files and games, since they have data relevant to those media types. 


IMG files are similar to ISO files in creating a backup image archive of the data on a disk. They mainly differ from ISOs in their use of compression. Since IMG files are compressed, some devices may be unable to read them.

Thus, if you are trying to transfer data between machines, we recommend using an ISO rather than an IMG format. However, if you’re trying to back up a system on the same machine, using an IMG file rather than an ISO can save some space.

How to Package an ISO File

To make an ISO file, you’ll need a utility to produce these files. Windows doesn’t come prepackaged with an ISO burner. So, you’ll need to download one separately if you have a Windows machine. We recommend WinCDEmu. First, ensure that all of your files are in one folder. Doing this small task will ensure that you have the smoothest experience.

Then, right-click on the folder and select “Build an ISO Image,” which will appear in the right-click menu once you’ve installed WinCDEmu. A dialog will open asking where you want to save the ISO image and asking you to give it a name. Once you enter the required information, you can sit back and let WinCDEmu do the work.

On a macOS system, you’ll want to open the Spotlight and search for Disk Utility to open that program. Then, go up to the File menu at the top of the screen and select “New Image,” which opens a second dialog where you’ll choose “Image from Folder.”

Select the folder you made for your ISO, give it a name, and choose where to save the file. Ensure that you change the “Image Format” in the final window to “DVD/CD master.” If you don’t do this, other machines may not read your ISO file. Once you’ve selected all the right choices, you can let Disk Utility work magic on your files.

ISO Files vs DMG Files

iso file
The DMG file is similar to ISO


However, only macOS systems can use them.

DMG is Apple’s proprietary disk image format. If you have a macOS device, you may receive DMGs when downloading applications for your computer. The main difference between ISO and DMG files is that DMG files are only compatible with macOS devices. If you want to use your image archive with other platforms, you must use the ISO format, as DMG files will be unreadable by non-macOS machines.

Frequently Asked Questions

What is an ISO file?

An ISO file is an exact image archive of the data stored on a physical storage disk, like a CD or DVD.

What are the advantages of ISO files?

ISO files provide an exact image of the disk data, including header and filesystem information.

What are ISO files used for?

ISO files primarily share data for large programs and operating systems.

What are the disadvantages of ISO files?

ISO files are slow to access and susceptible to data corruption. Any corruption within an ISO file renders the entire archive unusable, which is not true of all archive file types.

What are alternatives to ISO files?

Other archive files like RAR and ZIP can be used to compress and share large amounts of unrelated files. BIN and CUE files can share information that transfers data, like copy protection and track lists, such as music CDs. IMG files can create a backup image of your operating system while compressing the data and help store system backups that will only be used by the original system. 

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