A C.A.M.P. (Construction and Assembly Mobile Platform) is a player's personal home base, which can be relocated to almost any location on the map. Setting up a C.A.M.P. costs a small number of bottle caps and cannot be placed too closely to certain existing structures or other C.A.M.P.s.
If one connects to a server where their C.A.M.P. site has been occupied by another player's C.A.M.P., the returning player will have the option to try to find a different server where their C.A.M.P. can be placed, or to stay and have their C.A.M.P. objects and structures automatically stored in their C.A.M.P. inventory allowing for re-establishment at another location. Portions of a player's C.A.M.P. may be saved as blueprints to be used later or to quickly make multiple copies of complex structures.
Players can also build structures and decorate at any Workshop which they have claimed. Claiming a Workshop grants access to a bank of resources to be used in building up the workshop. Workshops also have resources which can be harvested by using an extractor. After claiming a workshop, the character is advised to build defenses before waves of enemies attack during an event.
Players may also need to defend their Workshops against other players who may contest their ownership of a Workshop. According to the Bethesda FAQ, "If a player attempts to contest a Workshop you own, or you attempt to contest another player's Workshop, you will be open to taking full damage from their attacks."
Much like in Fallout 4, the workshops revolve around resources: electricity, water, food, building materials, and defenses.