Dockerfile is a file which contains already mentioned steps for creating a specific Docker image. Dockerfile resembles shell script, but it's not that. This is a completely different language which is unique for Docker. When we create dockerfile, this implies that we should name the file in the same way, but it is not wrong to name it differently. The only thing we need to do here is to explicitly emphasise the name of the file, because the name dockerfile is already a common term.