ELI5: Explain Like I'm 5

Version vector

A version vector is like a timeline that is used to keep track of changes that happen in a system. It is like a list of when each individual change happened. For example, if you were writing a story, the version vector would tell you what order the different parts were written in and how old each part was. Version vectors help to make sure that everyone in the system is on the same page and is working on the same version of the story.