selector1, selector2,..
{
Declaration list;
}
A group selector is a way to select multiple HTML elements in CSS and give the same style to everything. To implement a group selector, we write a comma-separated list of selectors. Create a group selector to reduce code redundancy when different tags have similar styles. If you don't put a comma in the group selector, then the inside element will be selected instead of other elements. For example, if you put a p tag inside a Div element, then only that p tag will be selected. There are three types of group selectors:
p, h3{
background-color: grey;
color: black;
}
.p1, .head1{
text-decoration: underline;
color: darkblue;
}
#p1, #head1{
font-family: sans-serif;
color: darkviolet;
}
Read more about group selector