In the game, jumpgates are used to travel from sector to sector. All sectors, without a station, consist of asteroids and a beacon. Many have Player Owned Stations and may have items related to events run by GMs. Station sectors all have a planet within the sector. The player is the pilot of a spacecraft, acquiring wealth and status by engaging in trade, mining, and/or combat. Players may work on their own or together as members of a collaborative squad. Players can upgrade their spacecraft in various ways, including adding weapons, engines, shields, and other modifications and upgrades.
Source: Wikipedia, "Jumpgate: The Reconstruction Initiative", available under the CC-BY-SA License.