What is what does it mean when it says this person is unavailable on messenger?

When someone's status on Messenger says they are unavailable, it typically means that the person is currently not active on Messenger or may have turned off their chat availability. This could be due to various reasons, such as being logged out, having their phone turned off, or purposely setting their status to unavailable to avoid being disturbed. It does not necessarily mean that the person is not using Messenger at all, but rather that they are not currently accessible for messaging.