Exploring elegance: how "posh" and "luxurious" compare and contrast

What is similar?
Both words describe something that is high-end, elegant, or indicative of wealth and comfort.
What is different?
The word "posh" often conveys a sense of style, sophistication, or social status, particularly associated with British culture, while "luxurious" is more universally used to describe anything that provides luxury or comfort and is expensive or of high quality.
Which one is more common?

Examples of usage
Posh- They stayed at a posh hotel while visiting London.
- She always wears the most posh outfits to those events.
- The room was decorated with luxurious furnishings.
- They enjoyed a luxurious lifestyle at their seaside villa.