It is primarily used for mission reviews from different SG teams about their offworld discoveries, as well as a conference room for offworld travels. It was also used for extreme cases of emergency caused inside the base.
Also in the briefing room are projector screens, a spiral staircase which various personnel use to access the Briefing Room from the Stargate Operations room and computers for personnel usage.
In July 1997, following the attack on the empty SGC Embarkation Room that had resulted in the death of four Airmen and the capture of Senior Airman Carol Weterings as well as the subsequent attack on Abydos, the Briefing Room was seen being used for the first time in a meeting with members of the SGC and Dr Daniel Jackson with the group discussing what had happened. (SG1: "Children of the Gods")
In June 2002, the room was transformed into some briefing center so that various scientists including Dr. Rodney McKay could work on a solution to stop the active Stargate and later, the center was kept so that everyone could keep an eye on the progress involving Colonel Jack O'Neill who was using the X-302 hyperspace fighter's hyperdrive as a means of ensuring that the Earth was not destroyed when the still-active Stargate exceeded its time limit. (SG1: "Redemption, Part 1", "Redemption, Part 2")
In 2009, the briefing room was converted into a mission OPs center to observe the progress in Earth orbit concerning the Wraith Super-hive locating the coordinates for Earth. (SGA: "Enemy at the Gate")