A unimatrix was a type of subdivision used by the Borg Collective. (VOY: "Scorpion, Part II") Unimatrix was also a type of shielding technology used by Starfleet. (VOY: "Extreme Risk") The subdivision was used to designate groups of Borg drones and regions of space. A drone division could be further broken down into a trimatrix. (VOY: "Unimatrix Zero") The unimatrices of space were broken down into grids. The space inside a grid could be further specified as octants. (VOY: "Dark Frontier", "Drone", "Infinite Regress") The Borg also use the designation Matrix of regions of space. (VOY: "Scorpion, Part II")