Building explained

build diagram

Build is the process of executing one or more buildpacks against the app’s source code to produce a runnable OCI image. Each buildpack inspects the source code and provides relevant dependencies. An image is then generated from the app’s source code and these dependencies.

Buildpacks are compatible with one or more stacks. A stack designates a build image and a run image. During the build process, a stack’s build image becomes the environment in which buildpacks are executed, and its run image becomes the base for the final app image. For more information on working with stacks, see the Working with stacks section.

Buildpacks can be bundled together with a specific stack’s build image, resulting in a builder image (note the “er” ending). Builders provide the most convenient way to distribute buildpacks for a given stack. For more information on working with builders, see the Working with builders using builder create section.