The American Bar Association defines divorce mediation as follows:
A single neutral person, who may be a lawyer, a mental health professional, or simply someone with an interest in mediation, acts as the mediator for the couple.
The mediator helps the couple reach agreement, but does not give individual legal advice, and may or may not prepare the divorce agreement. Few mediators will process the divorce through the court. Retaining your own lawyer for independent legal advice during mediation is generally wise. In some locales the lawyers sit in on the mediation process, and in other locales they remain outside the mediation process.
Mediators do not have to have to be licensed professionals in most jurisdictions.