CI came about because lots of different people were working at the same time on large sets of code and they ran into what was termed “Integration Hell” when multiple people were working on multiple features at the same time using systems that did not allow for the same levels of integration as today’s systems, and basically they couldn’t get all the code to work together. It would take hours and hours or even days or weeks to get different groups’ features unravelled to the point where they could integrate these things together. So they created the concept of Continuous Integration, which basically means doing the integration continuously in smaller chunks instead of in gigantic blocks that will take forever to figure out how to fit together. Good idea, right?