what is ‘ruleset'?
A major difference between a rule set and individual data rules is the results they produce when they are executed. When you execute a rule set,
Are you referring to a CSS rule-set? https://css-tricks.com/css-ruleset-terminology/
(Isn't it amazing what a little bit of Googling can find?)
A rule or "rule set" is a statement that tells browsers how to render particular elements on an HTML page. A rule set consists of a selector followed by a declaration block.