The dd command in Linux explained
The dd command copies raw data between files and devices, and is often used to write an ISO to USB. It is one of the most useful commands for anyone using a live USB drive or a fresh Linux install.
Syntax
sudo dd if=input of=output bs=4M status=progress
Examples
sudo dd if=linux.iso of=/dev/sdX bs=4M status=progress: write an ISO to a USB device
Tip
dd overwrites whatever device you name without asking. Check with lsblk first, and use a graphical tool if you are unsure.
Keep learning
New to the terminal? Start with Linux terminal basics. You can try every command safely from a live session: see how to try Linux without installing it. Run man dd in a terminal for the full manual.
Frequently asked questions
How do I see every option for dd?
Run man dd for the full manual, or try dd --help for a short summary.
Do I need sudo to run dd?
Yes when writing to a device, because it needs administrator rights.
Is it safe to practise dd on a live USB drive?
Mostly yes, because a live session starts fresh each time. Be careful with commands that write to your internal disk, such as rm on a mounted drive or dd.