The scratch image is the most minimal image in Docker. This is the base ancestor for all other images. The scratch image is actually empty. It doesn't contain any folders/files ... The scratch image is mostly used for building other base images. For instance, the debian image is built from scratch as such: The rootfs.tar.xz contains all the ... More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.