A Satic Site Generator is a piece of software that takes some input - often simple text files or markdown files - and turns them into static HTML pages that can be served by most any web server.

This has many advantages:

1. You don't have to maintain and update any server software.
2. The site is more efficient as it does not require special processing on each page view.
3. There is less risk of "bit-rot" where the server software is unmaintained and the web site becomes inaccessible - something often seen on older blogs and web pages that used a CMS that reaches obsolescence.
4. The web site can continue to be readable years later as long as the HTML documents are still around.

They also have some disadvantages, mostly in terms of editing and work-flows which might seem unconventional or awkward to users accustomed to more graphical or cloud-based workflows.