Why put in front of the file name “_” or “_” in scss/css?

Question

Why put _ in front of the filename in scss?

_filename.scss - Why does it need _ ?

Answer 1

_ is used to denote partials. These partials contains the variables and internal functions that are required in the pre-processing stage, and they are not required to be compiled as css. _ partial templates contains utils, scss local variables and functions required in the compilation of the scss to css.