Built-in objects, native objects, and host objects

JS built-in objects are some of the functions and objects that are required to be implemented in the ECMAScript specification, including Object,function,number,boolean,array,

String,regexp,error,date,global,math. Where math is special, it's a static class, not a constructor. These objects (functions)

When the JS engine is initialized, it is already defined and can be used directly in the program or in the context of the function.

Native objects include built-in objects, including objects created at run time, such as user classes.

And the host object is the JS code in the running environment provided by the object, run on the browser JS, the host environment is a browser, and different browsers provide different

Host objects, which are self-defined outside the ECMAScript specification and injected into the JS engine, such as common window,console,htmlelement,

Image and so on.

Built-in objects, native objects, and host objects