Stargates are devices that creates a stable wormhole between two locatins. One gate connects to another and thus almost instantaneous travel becomes possible. When someone enters from a gate, it dematerilize this person and send it to destionation gate and destination gate recreate the person with the information that it receives from the other gate. This network of gates are spans across the galaxy. One gate may connect only one gate at the same time. If 2 gates are connect and another gate tries to establish a connection, it just fails. Every gate has a DHD. DHD is a device that used for dialing other gates. Every single gate has an address. By entering addressses in DHDs, gates are connect to each other.But DHD is not a requirement. A computer may function as the same. It is basicly an input device. But it has more functions that this. DHD also adjust drifts caused my motions of stars and planets. Earth's gate has no DHD thus Stargate Command must adjust drifts by manually. If not, a connection is impossible.The Stargate Network created by a race called Ancients. Other races know how to use it but only a few of them knows how they work. There are 39 symbols on each Stargate. 38 smybols are shared by all gates but every gate has a different point of origin smybolm. Destinations within the same galaxy requires entering 7 symbols. 6 symbols for destination's place in 3D space and 1 symbol for point of origin which is the stargate's location. Also, 8 and 9 symbols travel is possible. 8 symbols needed for intergalactic travel and 9 symbols needed for special destionations such the ship Destiny we talked about earlier. Stargates need massive amounts of power to function properly. Normally, Stargates are powered via DHDs. But it is possible to use other kinds of power sources. Another interesting part is that for matter, travel is possible only for one side. This means matter can go from where somebody dialed to destination gate. Other way is impossible. Energy is an exception for this.