Comments are useful in CSS for two main reasons:
1. Writing Notes/Reminders to Yourself Inside of a CSS File
2. Temporarily Hiding Rules/Declarations While Testing a CSS File
CSS comments will be ignored by the browser, although they can be viewed in the source code.
Each comment begins with /* and ends with */ just like PHP multi-line comments. CSS comments can span multiple lines, and can appear inside or outside of rule sets.
border: 1px dotted #000000;
/* margin: 25px; */