What is what does winter is coming mean?

"Winter is coming" is a phrase often used in popular culture, and most prominently associated with the television show "Game of Thrones." It serves as a warning that difficult times lie ahead, both literally in terms of the changing weather and metaphorically in terms of impending danger or challenges.

In the show, the phrase is often spoken by characters from the Stark family who come from the North, where winters are harsh and long. They use it as a way to remind others to be prepared for the challenges that lie ahead, and to be vigilant and cautious.

Outside of the show, the phrase has been adopted more broadly to signal the approach of challenging times or the need to be vigilant and prepared. It has become a popular meme and is often used in reference to various real-life situations or events where caution or preparedness is advised.