Lets See some Basic WWW HTTP study notes
- The World Wide Web (WWW) is a repository of information linked together from
points all over the world.
- Hypertexts are documents linked to one another through the concept of pointers.
- Browsers interpret and display a Web document.
- A browser consists of a controller, client programs, and interpreters.
- A Web document can be classified as static, dynamic, or active.
- A static document is one in which the contents are fixed and stored in a server. The
client can make no changes in the server document.
- Hypertext Markup Language (HTML) is a language used to create static Web pages.
- Any browser can read formatting instructions (tags) embedded in an HTML
- Tags provide structure to a document, define titles and headers, format text, control
the data flow, insert figures, link different documents together, and define executable code.
- A dynamic Web document is created by a server only at a browser request.
- The Common Gateway Interface (CGI) is a standard for creating and handling
dynamic Web documents.
- A CGI program with its embedded CGI interface tags can be written in a language
such as C, C++, Shell Script, or Perl.
- An active document is a copy of a program retrieved by the client and run at the
- Java is a combination of a high-level programming language, a run-time environment, and a class library that allows a programmer to write an active document and
a browser to run it.
- Java is used to create applets (small application programs).
- The Hypertext Transfer Protocol (HTTP) is the main protocol used to access data
on the World Wide Web (WWW).
- HTTP uses a TCP connection to transfer files.
- An HTTP message is similar in form to an SMTP message.
- The HTTP request line consists of a request type, a URL, and the HTTP version
- The uniform resource locator (URL) consists of a method, host computer, optional
port number, and path name to locate information on the WWW.
- The HTTP request type or method is the actual command or request issued by the
client to the server.
- The status line consists of the HTTP version number, a status code, and a status
- The HTTP status code relays general information, information related to a successful
request, redirection information, or error information.
- The HTTP header relays additional information between the client and server.
- An HTTP header consists of a header name and a header value.
- An HTTP general header gives general information about the request or response
- An HTTP request header specifies a client’s configuration and preferred document
- An HTTP response header specifies a server’s configuration and special information
about the request.
- An HTTP entity header provides information about the body of a document.
- HTTP, version 1.1, specifies a persistent connection.
- A proxy server keeps copies of responses to recent requests.