What is heads up?

Sure! "Heads Up" can refer to several different things depending on the context:

1. Heads Up Display (HUD): A technology used primarily in aviation and cars that projects information onto the windshield or a transparent display in front of the user. This allows the user to access key data without looking away from their usual viewpoints.

2. Heads Up Poker: A poker variant where only two players compete against each other. The dynamics of Heads Up play are different from multi-player poker, as it requires more direct competition and often involves different strategies.

3. Heads Up Game: A popular party game, available as a mobile app, developed by Ellen DeGeneres. The game involves one player holding a device on their forehead displaying a word, while the other players provide hints to help the person guess the word. It’s a lively game that tests knowledge and reaction speed.

4. Heads Up Notification: A type of notification that appears at the top of a device screen without interrupting the current activity. It is commonly seen on smartphones to alert users about incoming messages or updates.

5. Heads Up (General Use): The phrase "heads up" is an informal warning or alert to prepare someone for something. It can be used, for example, to warn someone of an upcoming event or to draw attention to something happening nearby.

If you have a specific context in mind, feel free to provide more details!