Earlier in this book, we discussed distributed versus decentralized systems. A distributed system is one that is made up of a number of computers, with the work of the system distributed across all of these machines. Typically, the computers in a distributed network are placed in different geographical regions to protect the system from outages such as power failures, natural disasters, or military events. A decentralized network is not only distributed geographically, but also in terms of authority and control. A distributed system such as the Amazon cloud can be worldwide in scope but still under the control of a central authority. A decentralized system has no central authority.





















































