BalenaEtcher is an open-source, cross-platform, and user-friendly software tool for writing disk images to removable storage devices such as SD cards, USB drives, and external hard drives. It is used to flash operating systems and other software onto these devices, making it possible to run the software on a computer or other device. BalenaEtcher has a straightforward, step-by-step process for writing images, and it verifies the written data to ensure a successful and reliable flash.