Culture is defined in the dictionary as:
1) the beliefs, customs, arts, etc., of a particular society, group, place, or time,
2) a particular society that has its own beliefs, ways of life, art, etc., and
3) a way of thinking, behaving or working that exists in a place or organization (such as a business).

High culture is aspects of culture that are deemed ‘superior’ and usually associated with (and consumed by) the elite in society: the well-educated or wealthy. It usually requires special education or training to develop and understand and is accepted by authoritative institutions as having ‘great value, importance, or significance. (Read: of greater value)
Whereas, low culture is seen as the opposite, meaning generally mass appeal popular culture. This mass appeal can be seen as rather basic, innocent, and escapist. Low culture often employs tropes and stereotypes that can be seen as offensive, emotional, and unbalanced (read: of less value).
Both terms ‘high’ and ‘low’ culture are seen as derogatory, or disrespectful toward the other. Popular culture, which changes more rapidly and, within this context is seen as a ‘lesser’ aspect of culture as it relates to socioeconomic status.

Examples of high culture include (but are not limited to) classical music, ballet, the fine arts, poetry, and some literature. Whereas examples of low culture include kitsch, slapstick, camp, escapist fiction, popular music, comic books, tattoo art, and exploitation films. A modern example of low culture could be reality tv programs and, opposite to this, examples of modern high culture include high-end fashion (think the Berkin bag or Louis Vuitton), food, or fads.

High culture is consumed by “well-rounded”, “well-read”, and “educated” folks whereas low culture is consumed by those “that don’t know any better.” Some things can transition from high to low culture when it becomes consumable by the masses. Low culture has also often been seen as “primitive” or “less developed”.
You Can’t Be Serious?!
If you have read this far, you hopefully can understand just how outdated these terms are in the 21st century, while understanding humans today as global, intercultural, and intermixed beings. One person’s high culture is another’s low culture and vice versa. This is especially true as many aspects of modern popular culture have become ‘canon’ as it were – having great value, importance, or significance since they were first produced.
Finally, if your ‘culture’ relies on degrading another person based on how they identify – or even how you identify them, maybe it is time to examine how ‘civilized’ these aspects of your culture really are.
Part of the problem here is that no matter how outdated these ideas are, they still remain. Luckily not to the extent of influence they had, say in the twentieth century. But, they can be found around the not-so-dark hushed edges.
Over to You
How has your understanding of culture changed over time? What is something that to your understanding began as ‘popular’ culture but has shown to have greater importance over time?