If you want to be a good web developer then having a sound knowledge in css is a must. It is css which makes a website look so beautiful. In small projects where there will be a few html files, writing pure css codes does not bother us much. When we start working on a large project then managing every files in a structured way is a must. If we continue writing pure css in such projects then there is a good chance that we have to write same css rules or codes in multiple files. As the number of css file increases, we will be losing our control over them. In order to get rid of such problem and gaining more control over css we should definitely use a css preprocessor.

Now the question is, what is a css preprocessor? According to Mozilla Developers org:

A CSS preprocessor is a program that lets you generate CSS from the preprocessor's own unique syntax.

This means that css preprocessors let us write css rules in a structured way which get converted to pure css by any compiler or loader. saas, less and stylus are the most popular css preprocessors.

Now let us discuss some reasons for using css preprocessors in web developement:

• Preprocessors let us use variables and functions that makes our developement easier.
• We can join multiple stylesheets into one by importing all of them into a main css file.
• Repititions can be avoided by writing the common rules together and using that as a mixin or function.
• Introduction of Darken and Lighten functionality.
• Introduction of nesting class which will give a style unique identity like having a class with similar name will not override the design if one is nested inside a particular class.
• All of this features together helps us writing css with less effort and time but efficiently.

So we should really start learning and using any css preprocessor to achieve an awesome developement experience. It will really be cool.