What is a keyword modifier?

What is a keyword modifier? A modifier is a word that in combination with your core keyword creates your long tail strategy (definition by Dan Thies). Most often a thematic modifier can be: a word of a general meaning (e.g. “guide”, “best”, etc);

For More Information Please Refer: https://www.searchenginejournal.com/how-to-organize-your-keyword-modifiers-to-create-long-tail-strategy/6526/