GULP plugins, gulp-useref plugin?

Question

gulp.js

gulp-useref - parses specific blocks and concatenates the styles and scripts described in them,
what does it mean, parses specific blocks?

Answer 1

Judging by the documentation, these are resources enclosed between build and endbuild:

<!-- build:css css/combined.css -->
    <link href="css/one.css" rel="stylesheet">
    <link href="css/two.css" rel="stylesheet">
    <!-- endbuild -->

In this block, we have included css files that will be combined into one combined.css