What Is DevOps? Unpacking CI, CD, and Agile Development

DevOps

DevOps is the combination of Development and Operations, a methodology that unites processes, methods, and systems to promote communication, collaboration, and integration between application development, operations, and quality assurance teams, aiming to break traditional silos.

DevOps emphasizes a culture where software developers (Dev) and IT operations staff (Ops) work together, automating software delivery and architecture changes so that building, testing, and releasing software becomes faster, more frequent, and more reliable.

It does not refer to a specific toolset; various tools can implement DevOps, but the essence is a comprehensive methodology rather than a particular collection of tools.

CI

CI stands for Continuous Integration, which means developers frequently commit code to the main branch, where each commit is automatically built and tested before merging.

The goal of CI is to quickly verify that new changes are good and suitable for further use in the codebase, ensuring that new and existing code integrate correctly.

CD

CD can refer to Continuous Delivery or Continuous Deployment, which are explained below.

Continuous Delivery

After CI completes automated build, unit, and integration testing, Continuous Delivery automatically publishes the verified code to a repository, ensuring the codebase is always ready for production deployment.

Each stage—from code merge to a production‑ready build—includes automated testing and deployment, allowing operations teams to quickly and easily release applications to production.

Continuous Deployment

In a mature CI/CD pipeline, the final stage is Continuous Deployment, which automatically releases the application to the production environment after it passes delivery.

Continuous Deployment means every change is automatically deployed to production, whereas Continuous Delivery means changes can be deployed but may be held back for business reasons; deployment requires delivery first.

Agile Development

Agile development focuses on embracing change and rapid iteration, emphasizing a mindset rather than a specific toolchain.

Relationship Between CI, CD, and DevOps

These concepts are interrelated; like the term CGI, which can refer to a protocol or tools implementing it, CI, CD, and DevOps can be understood at different abstraction levels.

References:

https://www.sohu.com/a/219547745_151779

https://blog.csdn.net/sinat_35930259/article/details/79429743

https://www.synopsys.com/blogs/software-security/agile-cicd-devops-glossary/

https://mp.weixin.qq.com/s/wCFM6Ln-iG_G-Um8cad0aA

https://www.redhat.com/zh/topics/devops/what-is-ci-cd

https://linux.cn/article-9926-1.html

https://www.mabl.com/blog/what-is-cicd

https://blog.csdn.net/CrankZ/article/details/81545439