"Class" (or "social class") - the set of concepts where people within a society are grouped into a set of hierarchical social categories according to their economic and social position - the most common being the lower, middle and upper classes.

"Upper class" (noun, adjective) - the social group that has the highest status in society and are usually rich.

"Lower class" (noun, adjective) has the lowest status in society and are usually poor.

"Middle class" (noun, adjective) is between lower and upper class that include professionals and business people and their families.

Definitions of social classes usually depend on the country, its culture and history.

There are aspects of a class structure in Australia, but for the most part, it is not really something that people are made aware of or a topic that is openly discussed.

• "Children of the upper classes are usually sent to expensive private schools."

• "Those from the middle classes are often highly educated but the same is not expected of those from the lower classes."

"Elite" (noun, adjective) - the richest, most powerful, best educated, or best trained people in a particular group or society.

Basically, this refers to the best of the best, like elite athletes, or elite troops, or intellectual elite.

Members of the upper classes are sometimes known as the "social elite."

• "The country's elite owned or controlled most of the wealth."

"Old money" (noun) - rich people whose families have been rich for a long time or the inherited wealth of established upper-class families.

"New money" (informal term) - people who have earned their wealth in the first generation, or the money owned by them.

Comparisons are often made to compare their lifestyles and spending habits.

• "Old money are born into wealth and tradition and usually have not experienced life without the money they currently have."

• "New money tend to be flashy and often show off their lavish lifestyles online."

"Nouveau riche" - the French equivalent for "new money," but this is a derogatory or disapproving term to describe people from a low social class who became rich in their lifetime and lack the manners, education, culture, and knowledge of those from old money.

To be honest I'm not sure how often this term is used when not referring to french history. But people might use nouveau riche instead of new money to sound smart.

"High" (adjective) can mean having power, great influence, or important position.

This would often be paired with other words to create compound adjectives or nouns. There are a few that relate to class.

"High class" (adjective) - of good quality, or of high social rank. It is often also used to mean very fancy, wealthy, or expensive.

It is implied that anything that looks or feels high class is catered to those who are wealthy or of high social rank.

• "All that gold interior in that restaurant made it look very high-class."

"High status" (adjective) describes someone who ranks highly in a social or professional hierarchy.

This is often used in a professional sense - financial managers, investment bankers, CEOs are considered high status jobs.

• "Women with high-status jobs are often unfortunately judged to be less romantically desirable."

"High society" (noun) - rich, powerful, and fashionable people.

• "It is often those from high society that are invited to royal weddings."