CSS minifyMinifies (downsizes) CSS
What does CSS minification do? - Removes extra characters from CSS that are not involved in styling the page. For example, it removes comments in the code, tabs, line breaks and other unnecessary pieces of code. After minification, all that remains is useful CSS that will work exactly the same as it did before minification.
Why CSS minification? - In order to increase the page loading speed, because the size of the data sent to the browser decreases.
What does page load speed affect? - It directly affects the search results. The faster the page loads, the higher it is in the list of pages that search engines give.