Survival servers, based on the singleplayer Survival mode are servers where the goal is to explore the world, farm and gather items, and build a base to survive. Some survival servers feel closer to vanilla Minecraft, while others add plugins and extra features. Land claiming is one common feature because it helps stop other players from breaking blocks or stealing from your base. Other common features include fly, jobs, sethomes, player shops, chest shops, and more complex in-game economies, usually using emeralds or server currency. Some servers have PvP disabled so you only need to worry about mobs, while others leave PvP on so protecting your items and base matters more. If you prefer a more community based survival world, SMP servers may be closer to what you want.