SASS (Syntactically Awesome Stylesheet) is a CSS pre-processor which helps to reduce repetition with CSS and saves time. It is more steady and intense CSS extension language that depicts style of document neatly and fundamentally.

Reason to use SASS :- 

1. It is pre-processing language which gives indented syntax (its own syntax) for CSS.

2. It gives a few components which are utilized for making templates that permits composing code all the more proficiently and simple to keep up.

3. It is super arrangement of CSS which implies it contains all the features of CSS and is an open source pre-processor, coded in Ruby.

4.It gives record style in great structure arrange than level CSS. It utilizes re-usable techniques, rationale explanations and a portion of the implicit capacities, for example, shading control, science and parameter records.

Feature of SASS :- 

1. It is more steady, capable and good with versions of CSS.

2. It is super arrangement of CSS and depends on the JavaScript.

3. It is known as syntactic sugar for CSS which implies it makes simpler route for client to peruse or express the things all the more obviously.

4. It utilizes its own syntax structure and assembles to meaningful CSS.

5. It is an open source pre-processor which is translated into CSS.

Advantages of SASS :- 

1. It permits writing clean CSS in a programming build.

2. It helps in writing CSS faster.

3. It helps designers and developers work all the more proficiently and rapidly.

Disadvantages of SASS :- 

1. It requires time for developers to learn new components exhibit in this pre-processor.

2. On the off chance that more number of individuals chipping away at a similar site, then will utilize the same preprocessor. A few people utilize the Sass and a few people utilize the CSS to alter the documents straightforwardly. So it will get to be distinctly hard to work with site.

3. There are odds of losing advantages of program's implicit component overseer.