“Asset Pipeline” is a fancy way of describing a process that compiles CSS, Javascript or other things you want to transform from a bunch of sources to
a production-ready output file.
While some static site generators have a standardized way of handling assets, Eleventy does not. That’s a good thing – it gives you the flexibility to
handle this any way you want, rather than forcing an opinionated way of doing things on you that might not fit your specific needs.
That flexibility comes at a price though: you need to figure out your preferred setup first.