div.classname in css file

Question

I have seen some developers write

HTML:

 some content 

CSS:

Answer 1

Exactly.

This is from the W3C spec:

For example, we can assign style information to all elements with class~="pastoral" as follows:

*.pastoral { color: green }  /* all elements with class~=pastoral */
or just .pastoral { color: green }  /* all elements with class~=pastoral */ 

The following assigns style only to H1 elements with class~="pastoral":

H1.pastoral { color: green }  /* H1 elements with class~=pastoral */

Given these rules, the first H1 instance below would not have green text, while the second would:

Not green
 
Very green