To know the sass structure [closed]

The & tells the pre-processor to add the parent selector in-front of the nested class. so this: .class-name{ background: blue &.class-name2{ background: red; } } would compile too: .class-name {background: blue;} .class-name.class-name2 {background: red;} The usage would be: <div class=”class-name”>This background is blue</div> and <div class=”class-name class-name2″>This background is red</div>