Initially thought it was an addon (or JS lib) that allowed for using Ruby as an embedded client-side scripting language that would parse in-line Ruby in the HTML.
Clearer once I realized it was closer to PHP or similar language usages.
Second also to the recommendation about a quick definition of ERB (Embedded RuBy). Had to look it up.
A few practical examples of what an actual user might want to do with HTML + ERB could be helpful.
- Client characteristics customization
- Previous use history customization
- The database Create, Read, Update, and Delete cycle using Herb
- A basic Content Management System example
- A basic e-commerce example
- A basic RESTful API example
Note: These are just my guesses based on what I "believe" its for.