This document discusses Bitbucket Pipelines, a continuous integration tool from Atlassian. It allows developers to automatically build, test, and deploy their code every time a change is merged into a shared repository. Pipelines uses Docker containers to run builds, allowing them to be fast, isolated from infrastructure concerns, and reproducible across environments. It also supports defining build configurations as code to make the pipeline definition versioned, reusable, and easy to understand at a glance.