In this tutorial you will learn how to burn an ISO image to your USB flash drive or harddisk. Balena etcher is a cross platform app that allows you to create bootable devices in a matter of seconds, it is very easy to use and doesn't require any technical knowledge, so feel free to try balena etcher.
Since balena etcher is a cross platform app, you can run in Linux, Windows and MacOS. However, in this tutorial we're going to explain how to use it on Linux.
Step 1 - Download Balena Etcher
Go to the official website of Balena Etcher- https://www.balena.io/etcher/ and click the Download button.
You should see the zip file downloaded on your downloads folder, the file is called balena-etcher-electron-1.7.9-linux-x64.zip
This zip file contains balenaEtcher-1.7.9-x64.AppImage, so simply extract the zip file to the directory where you want. For example, I extracted the zip file on my Desktop so I can access it faster without going through unnecessary directories.
Step 2 - Launch Balena Etcher
Balena etcher comes in the .appimage format, which means you don't have to install anything on your system, all you have to do is to run the app and use it. Appimage format is a portable format of the app and all files that balena etcher requires to run are inside the package.
Double click to balenaEtcher-1.7.9-x64.AppImage to launch it, and the app should look like this.

You can also launch balena etcher using the terminal, run the command below
./balenaEtcher-1.7.9-x64.AppImage
Step 3 - Select ISO
Balena Etcher allows up to three methods of choosing the ISO file
1) Flash from file - By selecting an local ISO (ISO downloaded on your computer)
2)Flash from URL - For example, if you have uploaded the ISO file to your server you can choose this option, make sure the url of the iso file is a direct link
3)Clone Drive - Allows you to clone a drive, let's say you have an usb flash drive that already contains the ISO file and you want to clone the same flash drive to another one.
In this tutorial I went with the first option : Flash from file , click flash from file and select the ISO file.

Step 4 - Select the Device
Once you have added the ISO file on balena etcher, now you need to plug in the usb flash drive or any other device where you want to burn the ISO, and click the "Select Target" button as shown on the image below

This will open a window that will show a list of the devices that are already plugged in, choose your device by checking the box and click the Select button

Step 5 - Burn the ISO
After choosing the ISO file and the device that you want to burn the ISO file, simply click the Flash button and the burning will start.

You should see this window

Once flashing has been completed, balena etcher will validate the ISO file to make sure that everything went fine and that the usb flash drive it's not corrupted, even if you've done this multiple times and you know that your flash drive will work, don't skip the validation process.

When flashing and validation processes have been completed, you are good to go and boot using your device.

Conclusion
By now you should know how to burn ISO files into your device with Balena etcher.