A safezone is an area of the map where monsters will not spawn or be able to enter under common sircumstances. Although there are certian events that will cause the safezone to become comprimised such as Anti-Nether Devices failing.
Area in which the player is safe and where monsters will not spawn.
Along with the Safezone preventing any sort of PVP or PVE combat it also acts as a trade center alowing players to access an ingame marketplace useing cash or gold. Items you pick up around the map will act as the one of many ways to gain cash by selling these items the trade center will grant you small sums of cash. Safezones and Outposts are also the only location where you can aquire Courier Bags, another way of gaining cash. The safe zone is the only outpost with a purple trader, which you bring the lzs escort packages to.