Some state Real Estate Commissions, notably Florida's after 1992 (and extended in 2003) and Colorado's after 1994 (with changes in 2003), created the option of having no agency nor fiduciary relationship between brokers and sellers or buyers. Having no more than a facilitator relationship, transaction brokers assists buyers, sellers, or both during the transaction without representing the interests of either party who may then be regarded as customers.
As noted by the South Broward Board of Realtors, Inc. in a letter to State of Florida legislative committees:
"The Transaction Broker crafts a transaction by bringing a willing buyer and a willing seller together and assists with the closing of details. The Transaction Broker is not a fiduciary of any party, but must abide by law as well as professional and ethical standards." (such as NAR Code of Ethics)
The result was that in 2003, Florida created a system where the default brokerage relationship had "all licensees ... operating as transaction brokers, unless a single agent or no brokerage relationship is established, in writing, with the customer" and the statute required written disclosure of the transaction brokerage relationship to the buyer or seller customer only through July 1, 2008.
In simple words it means the agent is there to bring 2 parties together and facilitate the transaction, but does not represent one or the other (when being used by both seller and buyer).