What is DevOps, and how does it benefit software development?

At software organisations, we build, test and deploy our code continuously. Picture me as a developer adding a new button to toggle the theme of my website from dark to light. Once I write the code that implements that functionality, I "save my changes" to a source code control system. DevOps engineers design that system through automated tasks. The system triggers actions to build and test my website. If everything goes well, the systems updates my website with those new changes. The outcome of these actions is that our product now has a button that toggles the theme from light to dark. The great thing about this is that as a developer, I didn't have to care about the process. I just had to save my changes.