Short for "JavaScript, API, and Markup". In short, the idea is that a website/webapp doesn't need server side processing, but can be precompiled to a set of markup files and scripts that communicate with APIs to deliver dynamic and data-bound features.
In fact, this site - my blog - is built around the same philosophy. It is built on Statiq, which is a static site generator that works with .NET. (I had originally tried out 11ty, which was also fine, but built on Nodejs, and I really loathe the Nodejs ecosystem at this point)
Read more on the blog: https://botched-deployments.com/posts/about-datatables