javascript learning first-day

1.javascript is a client-side language, its purpose is designed to perform tasks on the user's machine rather than on the server.

     1.1 javascript is not allowed to write the language on the server machine;

　  1.2 Javascript is not by its own can not close the window that opens.

　  1.3 JavaScript can not read information from a web page that has been opened from another server. In other words, you can not read the page

Other information in the window is already open, exploratory and therefore can not access the site surfers also access to other sites.

 

AjAX：

1.Ajax is a way to create interactive web applications the way. Asynchronous JavaScript and abbreviations XML (Asynchronous JavaScript and XML),;

Glossary:

2.AjAX related technologies:

　　　　　　 XHTMl、

　　　　　　　CSS (Cascading Style Sheets),

 　　　　　　　　Use javaScript access DOM (Document Object Model, Document Object Model),

　　　　　　　　　　The JSON or XML, which is a format for transmission of data between the server and the client,

　　· XMLHttpRequest, used to obtain data from the server.

Benefits 3.Ajax: The application processing takes place mostly in the user's browser and the server data request is often very short, so you can use Ajax to build feature-rich applications, these applications rely on web-based data, but its performance far more than the old fashioned way, because the old-fashioned method requires the entire server returns an HTML page in response to user actions.

 

CGI (Common Gateway Interface), is one of a standard interface, the external expansion server applications and Web server interaction way to interact with the client.