Builder is the kpack configuration for a builder image that includes the stack and buildpacks needed to build an image from your app source code.
ClusterStore A store resource is a repository of buildpacks packaged in buildpackages that can be used by kpack to build images. Later in this tutorial you will reference this store in a Builder configuration.
ClusterStack A stack resource is the specification for a cloud native buildpacks stack used during build and in the resulting app image.
kpack Tutorial
https://github.com/pivotal/kpack/blob/main/docs/tutorial.md
TGIK Episode
https://www.youtube.com/watch?v=4zkRX9PSJ5k