.. Introduction of Schema.org Schema.org Basics ****************** Schema.org is a collaborative, community activity with a mission to create, maintain, and promote schemas for structured data on the Internet, on web pages, in email messages, and beyond. .. _two_main_types: Classes and Properties ---------------------- Everything in Schema.org schema is either an item type/class or a property. For example, `Person `_ is a schema.org Class. Every Class has its own properties. For example, `Address `_ is a schema.org Property. .. _hierarchical_structure: Hierarchical Structure ---------------------- All classes in Schema.org schema is defined in a hierarchical tree structure. `Thing `_ is the root of this structure. And all classes besides `Thing `_ will have its own parent class(es) and may also have its own child class(es). For example, `Patient `_ is a subclass(child) of `Person `_ and `Person `_ is a subclass(child) of `Thing `_. Moreover, properties could also have parent properties. For example, `isbn `_ is a subproperty(child) of `identifier `_. .. _inheritance: Inheritance ----------- All classes defined in Schema.org schema will have its own specific properties. For example, `Address `_ is a property of `Person `_. In addition, all classes will inherit the properties of its ancestors. For example, `description `_ is a property of `Thing `_. And since `Person `_ is a subclass(child) of `Thing `_, `Person `_ inherit the property `description `_ from its parent `Thing `_.