Exchange-based vs over-the-counter (OTC) I read an article about China ban on exchange, which mentions that 


  ... the ban on exchange-based cryptocurrency trades will not extend to over-the-counter (OTC) transactions. 


I am confused over the terms exchange-based and OTC. What are the differences between these two?
Exchange-based transactions, ;


  Exchanges bring together brokers and dealers who buy and sell these objects. These various financial instruments can typically be sold either through the exchange, typically with the benefit of a clearinghouse to cover defaults, or over-the-counter (OTC), where there is typically less protection against counter-party risk from clearinghouses,
  
  This is the case if you for example buy altcoins on Bittrex.com, Or poloniex.com All these transactions Are ""Exchange-based".


This means in the case of cryptocurrencies, that it is done through a third party, and you don't know the seller of the currency.

OTC transactions : 


  Over-the-counter (OTC) or off-exchange trading is done directly between two parties, without the supervision of an exchange. It is contrasted with exchange trading, which occurs via exchanges.