Question

Consider:

p {
  ...
}

.foo {
  ...
}

#bar {
  ...
}

What is the correct name for these statements in CSS? I’ve seen them called selectors, rules or rulesets, but which is correct?

Answer 1

A rule would be considered:

p {…}

A selector in this case is:

p

A rule is made up of selectors and declarations. A declaration is property:value so the entire rule would be:

selector { property:value }

A rule can have multiple declarations and multiple selectors so we can actually have:

selector, selector2
{
  property:value;
  property2:value;
} 

A rule set would be multiple rules.

Here’s a quick source on this or the CSS 1 Specification.