A builder is an OCI image with all the inputs needed for a buildpacks build, including the build-time base image, a reference to a runtime base image, a lifecycle, and a set of buildpacks.
Declare information about application source code, to be included as metadata in the application image.
Environment variables
are used to configure buildpack behavior. They may be specified by:
A stack is the grouping together of the build and run base images, represented by a unique ID.