In this context, a revocation hearing is most likely a motion to revoke your bond. That said, there's insufficient information to form an opinion s to what's going on in this case and more importantly what, if anything, you can do to protect yourself. If you're represented by counsel, I urge you to seek out their input & guidance. If you don't have an attorney, hire one immediately.
Posting an answer to your question does not create an attorney / client relationship such that you can or should rely on the information provided herein to take action. Instead, it is intended to simply provide you with information. I am not your lawyer and cannot provide you with legal advice unless and until I am hired to do so.
It's a hearing to determine whether the court will revoke your probation.
It appears you've been accused of violating your probation and, presumably, you entered a denial. The court set a revocation hearing wherein the State will attempt to prove to the satisfaction of the court whether you willfully and materially violated a term or condition of probation. Witnesses may be called; hearsay may be admitted (but may not be the sole basis of the proof); and, with some limitations, you could be called by the State as a witness. If proven, the court will impose a sentence to include anything he or she could have given you on the underlying charge. If it is not proven, you will be returned to probation.
You should have a lawyer on your side. Even if it's a minor violation, a lawyer is a good idea.
Lastly, you might want to spend a Monday morning or afternoon or whenever your judge has VOP revocation hearings and simply observe. You'll quickly see how serious this is as people come in the front door and leave out the back door.