Encapsulation of the three main characteristics of object-oriented (C #) is to integrate data or functions into units. People who use this unit do not need to know how to implement it internally, you only need to call the interface provided by the encapsulated unit. encapsulation provides an effective way to protect data from Accidental damages. encapsulation: 1. attribute encapsulation of fields 2. encapsulate multiple parameters of a method into an object. put a bunch of code with a specific function in a method. 4. encapsulate some common types or methods into a set of programs. The advantages of good encapsulation are as follows: 1. Callers do not have to worry about the specific internal implementation. by publishing an interface, they can simply implement the call (and also hide the technical details ). 2. good encapsulation can reduce coupling 3. as long as the external interface does not change, you can modify the internal implementation as needed, which can effectively cope with changes. 4. class has a concise and clear external interface, reducing the user's learning process 5. code can be reused. Write frequently used functions into a method.