This document discusses object-oriented programming concepts like classes, objects, methods, and inheritance. It mentions that a class defines objects and methods, objects are instances of classes, and subclasses inherit properties and behaviors from their parent classes. Comments are also included as a way to annotate code.

1. 1.Object
Class
Class
Class
Object
2. Comment
Compile Error
One-line Comment
Multi-line Comment
Document Comment
3. class
Object
Method public
Service

2. Method public Class
Class
Class Method
Objects
Parameters
Method, Service, Class
Class Super Class
method Class