@import rule is not an invention from SassScript. It has actually derived the rule from CSS. Using the @import rule, you can import CSS and SCSS (Sass) files.
You can access the members (functions, variables and mixins) from another modules after you import those modules. Bunch of CSS files you want to combine? Use @import to do so.
The difference between CSS imports and SCSS (Sass) imports is that SCSS imports are handled completely during the compilation of the files while CSS imports require the browser to make multiple requests.
CSS and SCSS imports have the same syntax. The advantage of SCSS imports is that you can import multiple files in a single import statement like this:
@import 'foundation/code', 'foundation/lists';
Note that you don’t need to use quotes while importing URLs in Sass (indented) syntax.
Sass will remove @import rules entirely in future. Use @use rule instead.