The “bankruptcy trustee” is the representative of the bankruptcy estate, which is made up of all of your property at the time you file your bankruptcy case. The job of the trustee is to review all of the disclosures you made when you filed your case, and to investigate your financial affairs. The trustee does this to make sure you aren’t cheating any of your creditors out of anything they’re entitled to under bankruptcy law.
The trustee also looks after the creditors’ interests by liquidating, or selling off, any of your property that doesn’t fit into any of the exemptions that allow you to hold onto your property. The trustee is also in charge of distributing that money to your creditors.
Another thing the trustee does is to make sure that you didn’t make any fraudulent or voidable sales or gifts to anyone who isn’t one of your creditors, and to bring that property back into the estate if you have.