It's a casual, informal way to say goodbye.
Here are some other ways to say goodbye in Dutch, depending on the situation:
* "Dag" - This is a more formal way to say goodbye.
* "Tot ziens" - This means "see you later".
* "Tot morgen" - This means "see you tomorrow".
* "Tot straks" - This means "see you soon".
* "Welterusten" - This means "good night".
The best way to say goodbye in Dutch will depend on the context and your relationship with the person you are saying goodbye to.