If you want to restore a previously saved image of an SD card, you can often use various command line tools such as the terminal. Restoration can easily become a pain: The progress of the recovery is not displayed or the recovery is simply unreliable - the SD card in Raspberry Pi still doesn't want to boot at the end. A new tool for Mac, Windows and Linux with graphical user interface solves the problem: Etcher.
If you use your Raspberry Pi or other single-board computers in not necessarily gentle environments, you know that the file system can suffer unpredictable power fluctuations. Often only a restore of a previously (hopefully) made backup or the repair of the SD card's file system on a Linux host will help.
However, as I usually have current backups and only rarely use the log data that has been generated in the meantime, I usually use the SD card for this purpose. And that's a pain in the ass every single time.
The image does not fit to the physical size of the SD card, the image was written unreliably (checksum error) and in the end my Raspberry won't boot from the card. All over again...
This is over now, because there is a new tool now: Etcher is an open source program for reliable recovery of SD card images with graphical user interface. It not only recovers the SD card from ALL common backup formats (. gz,. zip,. img etc.), it also checks the target card and configures it accordingly and then verifies the written image.
If Etcher says that the image was written successfully, the SD card will work in the target device. You can count on it.
You can find the excellent tool here: https://etcher.io/