Empire space
Empire space, often shortened to "Empire" (And not to be confused with the Amarr Empire), or "High Sec", is the area of space where the four major factions, The Amarr Empire, Minmatar Republic, Caldari State, and Gallente Federation as well as The Khanid Kingdom and Ammatar Mandate hold sovereignty. Empire space encompasses the space with a positive security rating and some systems in 0.0
As sovereignty is already held by by one of the factions, alliances may not lay claim to sovereignty anywhere in Empire space. In addition any POS towers anchored in high security space must be supplied with starbase charters from the holder of sovereignty as well as having high standings with that faction.
Empire space contains the majority of pilots in Eve and as a direct result, most of the traffic and commerce.