javascript--the client Web browser scripting language.
What is language?
Used for communication, with complete syntax and explicit semantics .
A complete set of JavaScript implementations consists of three different parts:
1,ecmasript (CORE)
Just a description that defines all the properties, methods, and objects of the scripting language. That is, a language has a clear code of use and use of the method.
It provides the syntax, operators, and basic objects of JavaScript that are necessary to implement common program design tasks.
2,dom
The DOM is an API for working with HTML and XML, and describes the methods and interfaces for working with Web page content.
3,bom
The BOM describes the methods and interfaces that interact with the browser, primarily dealing with browser windows and frames.
JavaScript Advanced Programming--Learn from scratch (1)