It’s completely free and open source made for all types of websites and web environments. The Hugo homepage explains more about features and why developers may rely on such an engine.
Here’s a brief explanation from the Hugo website:
“Hugo is quite possibly the easiest to install software you’ve ever used, simply download and run. Hugo doesn’t depend on administrative privileges, databases, runtimes, interpreters or external libraries. Sites built with Hugo can be deployed on S3, GitHub Pages, Dropbox or any web host.
Organize your content however you want with any URL structure. Declare your own content types. Define your own meta data in YAML, TOML or JSON. Use indexes to group your content however you want. Best of all this is all done with virtually no configuration, Hugo just works.”
Devs who enjoy picking apart code should visit the Hugo repo on GitHub. It contains all the major docs + installation instructions for Hugo binaries.
You can also visit the online documentation which gives an overview of Hugo & how it works a real-world setting.