FROM — Specify which image to use for the container.
RUN — Run a command on the container. Used for things like installing packages, etc.
EXPOSE — Open ports from the Docker container to the host.
CMD — The default command to run when the container is started. Can be overridden from the command line at runtime.
ENTRYPOINT — Similar to the CMD option in that it will be the default command that is run but this one cannot be overridden from the command line.
COPY — The COPY instruction copies new files or directories from <src> and adds them to the filesystem of the container at the path <dest>. COPY has two forms:C OPY <src>... <dest> and COPY ["<src>",... "<dest>"] (this form is required for paths containing whitespace)
ADD — The ADD instruction copies new files, directories or remote file URLs from <src> and adds them to the filesystem of the container at the path <dest>. ADD has two forms: ADD <src>... <dest> and ADD ["<src>",... "<dest>"] (this form is required for paths containing whitespace)
WORKDIR — The WORKDIR instruction sets the working directory for any RUN, CMD, ENTRYPOINT, COPY and ADD instructions that follow it in the Dockerfile.
ONBUILD — The ONBUILD instruction adds to the image a trigger instruction to be executed at a later time, when the image is used as the base for another build. The trigger will be executed in the context of the downstream build, as if it had been inserted immediately after the FROM instruction in the downstream Dockerfile.
Other can be found - https://docs.docker.com/engine/reference/builder/