Permissionless

      Within the world of blockchain and digital assets, project governance falls into one of three archetypal classifications; public private and hybrid. How a governance archetype is deduced depends on it level of permissibility; and permissibility is the ease with which a new participant can join the consensus of a network. 

Private = Permissioned
Hybrid = Permissioned (regionally)
Public = Permissionless

     Permissionless blockchains have a governance structure that allows for participants to join and leave the network at will. In the case with Bitcoin, in order to join the network to participate in consensus somebody just needs a device, no authority prevents them from just plugging in. Thus making it extremely fluid and easy to join.