The Galaxy rotates clockwise as seen in the map above. Galactic directions are given as zenith ("up"), nadir ("down"), coreward (toward the galactic centre), rimward (toward the galactic edge), spinward (in the direction of galactic rotation) and trailing (opposite the direction of galactic rotation).
The United Federation of Planets divides the Galaxy into four wedge-shaped quadrants, labelled Alpha, Beta, Gamma and Delta. Sectors are mapped according to coordinates centred in space on the galactic ecliptic, on a radial line from the galactic centre through Earth. The sector containing this point is referred to as Sector 0-0-0. Earth, Alpha Centauri, Andoria and Tellar, four of the five founding members of the Federation, are in the sector immediately to zenith, Sector 0-0-1. Vulcan, the fifth founding member of the Federation, is in the Vulcanis Sector, immediately rimward of Sector 0-0-1.