A model of the business network
Now that we've understood the types in the business network in natural language, let's see how they are defined technically. On the left-hand side of the Playground, select Model File.
 In this business network, there is only one model file that defines the participants, assets, transactions, and events. In a bigger application, we'd keep the information from different organizations in their own files, and often in their own namespace. It allows them to be kept separate but brought together when necessary. Let's see how namespaces work.
Namespaces
Our example uses a single namespace:
namespace org.acme.loc
This namespaces says that the type definitions in this file have been defined by the Acme organization's letter of credit process. All this is a short name! Use namespaces–they'll help you clearly separate, and more importantly, communicate, your ideas. It is recommended to use a hierarchical name so that it's clear which organizations in the network are defining...
