Blockchain
Question # 1 What is a blockchain?
A blockchain is
 a secure platform where buyers and sellers can store and exchange value.  an operating system for marketplaces, networks, and communities. https://www.hyperledger.org/ http://sloanreview.mit.edu/article/how-blockchain-will-change-organizations/
The blockchain enables peer-to-peer payments – resulting in a decentralized sharing economy.
http://blockgeeks.com/guides/what-is-blockchain-technology/
Question # 2 How does a blockchain work?
http://www.swissinfo.ch/eng/joining-the-blocks_how-blockchain-could-soon-affect-everyday-lives/43003266
How does a blockchain work?
Blockchain transactions are continuously verified, cleared, and stored by the network in digital blocks that are connected to preceding blocks, thereby creating a chain. Each block must refer to the preceding block to be valid.
http://sloanreview.mit.edu/article/how-blockchain-will-change-organizations/
Question # 3 What advantages of a blockchain are there?
3 advantages of a blockchain: 1. There is no central database. A blockchain runs on computers provided by volunteers around the world. 2. Anyone can view the blockchain at any time. It is open and public. 3. A blockchain uses heavy-duty encryption to maintain security.
http://sloanreview.mit.edu/article/how-blockchain-will-change-organizations/
The blockchain / trust economy trend represents a remarkable power shift from large, centralized trust agents to the individual. With the development of blockchain, business and government will have to create new ways to engage the individual. https://dupress.deloitte.com/dup-us-en/focus/tech-trends/2017/blockchain-trust-economy.html
Blockchain technology facilitates the emergence of new forms of organizations, which have no hierarchical structure. Users contribute to and govern the platforms. They are also shareholders of the platforms. This will enable people to cooperate toward the creation of a common good, while ensuring that everyone will be duly compensated for their efforts and contributions.
https://hbr.org/2017/03/what-blockchain-means-for-the-sharing-economy
Question # 4 What are some concrete examples?
https://akasha.world/, https://steem.io/ and http://www.synereo.com/ are applications / social networks that have been deployed on a blockchain. These applications / social networks work without a central platform and without an organization to manage the network. The platforms are run in a decentralized manner - aggregating the work of disparate groups of peers which coordinate themselves through a set of codebased rules enshrined in a blockchain. https://hbr.org/2017/03/what-blockchain-means-for-the-sharing-economy
https://openbazaar.org/ is a decentralized marketplace. The peer-to-peer network is not controlled by an organization. It is a community of people who want to engage in trade directly with each other.
https://hbr.org/2017/03/what-blockchain-means-for-the-sharing-economy https://openbazaar.zendesk.com/hc/en-us/articles/207982443-How-does-OpenBazaar-work-
http://lazooz.org/ and https://arcade.city/ are ridesharing platforms. The platforms operate in decentralized ways without a centralized operator. The platforms rely on a blockchain to reward drivers contributing to the platform with specially designed tokens that represent a share in the platform. https://hbr.org/2017/03/what-blockchain-means-for-the-sharing-economy