This document discusses continuous integration (CI), including an overview of CI, its principles, and advantages and disadvantages. CI is a software development practice where developers regularly merge code changes into a central repository, which then triggers an automated build and test of the code. The principles of CI are to maintain a code repository, automate builds and deployments, make builds self-testing, commit to mainline daily, build every commit, keep builds fast, test in a production-like environment, and make builds easily accessible. Advantages are easy code reversion, early issue detection, immediate testing and feedback, while disadvantages are initial setup time and needing a test suite.