Computer FundamentalsInstructor: Jun YanThursday (3, 4), N229, South Campus

Lecture 8:Computer networks and Internet service

吴秋盈 2015050484

This lecture covers the following topics:File formats ,Computer networks and internet service

1.Course announcement:

The manual of experiment of HTML is uploaded,and on Dec.3 and Dec.10 we will have experiment course in Room 503

2.Review of last lecture:

(1)Operating system--the key point is its five activities:

Manage processor resources:

each process receives its share of microprocessor cycles (we use the example of QQ,word and IE,as the picture shows )

Manage memory

Keep track of storage resources

④Get involved with peripheral devices

⑤User interfaces

(2)File System--the key point is file names and extensions

Physical File Storage and File Formats

●Storage media must be formatted before it can store files

●Format a hard disk will lose all you data and virus

●Install OS in a seperate partition is a good idea

●Deleting a file changes the status of that file’s clusters to empty and removes the file name from the index file,but the file’s data is still there

●Files in the Windows Recycle Bin and similar utilities can be undeleted

The part of Software is over~

and we watch a video about types of software

3.The new lecture

(1)Web Basics

The Web is a collection of document,image,video and sound files that can be linked and accessed over internet using a protocal called HTTP

HTTP Request

[Client] [Server]

HTTP Response

A Web server is an internet-based computer that accepts requests from browsers

A Web page is the product or output of one or more Web-based files displayed in a format similar to a page in a book

④A Wed browser is a client software that displays Web page elements and handles links between pages

(2)HTTP

Every Web Page has a unique address called a URL(uniform resource locator)

E.g.

showbiz/ moxies.htm

Web protocol standard web server name folder name file name and file extension

HTTPmessagesflowbetweenabrowserandaWebserver

  1. write the URL
  2. Client(The browser opens a socket and connects to a similar open socket at the Web server)
  3. →(The browser generates and sends an HTTP message through the socket)
  4. ←(The server sends back the requested HTML document through the open sockets)
  5. Off(After sending the response,the server closes its socket and the browser closes its socket)

(3)HTML

HTML is a set of specifications for creating documents that a browser can display as a Web page

(4)HTML Scripts

HTML scripts can perform specific actions or respond to specific user actions

Example:VIDEO TIME!<html>

<body>

Hello world

</body>

</html>

(5)Web Browsers

●Help you access Web pages

●Upgrade to new browser versions as they become available

●Help applications extend browser’s ability to work with file formats

(6)Cookies

Definition: Small chunk of data generated by a Web server and stored in a text file on computer’s hard disk

●Your computer does not have to accept cookies

--You’d better not store password in cookies

(7)Web Page Authoring

●What tools can one use to create web pages?

-HTML conversion utility,such as word.Use “Save as”

-Online template-like tools,such as google sites,wordpress

-Software,such as Adobe Dreamweaver

-Text Editor

References:

[1].Website:

[2].My notebook

That’s all.Thank you!

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