Claims is Survival’s way of protecting builds and chests. You do this by holding a golden shovel in your hand and right clicking two points diagonal from each other which will create an area that only you and people you trust can build and interact with. Claims is more customisable then plots as you are able to select what people can do, for instance you can let them ONLY interact with chests by doing /containertrust (playername), you can check out more commands at Survival Commands. However, with Claims you only have a certain amount of blocks. You start off with 10 blocks which is enough for a 10 by 10 area, if you are using a golden shovel and not doing /expandclaim, the smallest area you can make is 100 blocks. You get more claims blocks everyday that you log in.