A stack build is a deployable snapshot of a stack. It contains all built images and their configurations, and can be directly deployed to an environment. The philosophy is the same as with an individual container image -- they are atomic, and hold everything they need to be deployed.
When you first import a stack, it will also create an initial build. Every build generates a "build log", containing all the output generated when Cycle built the images.
If you've got questions about the platform or need some help getting started, our team is more than happy to assist. Whether you're new to containers or just new to Cycle, reach out to us via livechat by clicking the blue circle in the bottom right corner. Join our Slack channel, and get help from the dev team or other members of the community, and check out our Roadmap to see what's planned for the future!