Description : Purpose and usage of mixins in SASS.
Answer :
Mixins inSASS are reusable chunks of code that allow you to include the same setof styles in multiple places. You define a mixin using the `@mixin` directive and include it in your CSS using `@include`. For example:`@mixin border-radius($radius) { border-radius: $radius; }` can be included in any selector with`@include border-radius(5px);`.