Nog was a Ferengi, the son of Rom and Prinadora, and the nephew of Quark. He was the first Ferengi to enter Starfleet, and served aboard Deep Space 9 and the USS Defiant during many of the most important battles of the Dominion War.
As a young Ferengi, Nog was required to memorize the Rules of Acquisition and study the philosophy of the Great Material Continuum. In time, he was expected to become a merchant and to acquire wealth like a good traditional Ferengi male. At some point during the latter years of the Cardassian Occupation of Bajor, Rom and Nog took up residence on Terok Nor and began work as waiters in Quark's bar. In 2369, Nog was still living on Terok Nor when the Cardassians withdrew.
Nog quickly met Jake Sisko, Commander Sisko's son, as there were only a few children on the newly renamed Deep Space 9 after the Bajoran Provisional Government asked Starfleet to take over administration of the station. As a result, Jake and Nog spent a lot of time together and soon became close friends. They had many adventures and misadventures together and often engaged in mischief; occasionally getting in trouble for playing pranks on the station. Much of their time was spent on the Promenade, where they watched the passengers disembark.