Maps in Sass hold pairs of keys and values, and make it easy to look up a value by its corresponding key. They’re written (<expression>: <expression>, <expression>: <expression>). The expression before the : is the key, and the expression after is the value associated with that key.

Example

// Declaration
$our-custom-font-weights : (
  "regular": 400,
  "medium": 500,
  "bold": 700,
);

// Usage
font-weight: map-get($our-custom-font-weights, bold); // --> font-weight: 700;