fflib-apex-extensions/docs/primitive-domains.md

fflib-apex-extensions

Primitive Domains

A huge benefit of using primitive domains, is that you write less code. Instead of:

List<String> myStrings = getSomeStrings();

You can write:

Strings myStrings = getSomeString();

It is a small thing, but it makes things looks much nicer.

One other benefit is that you can encapsulate more logic as Lists. You can see these lists as a Domain. Take a look at the SObjects primitive domain, it is the new source for extending domain classes.