The Internet (Downloading and Uploading)
Now that you know how pages are sent to and fro,
let's learn about how information is transported from one computer
to another. HTTP - Hyper Text Transfer Protocol is the protocol
or rules that the Client (users computer), and the Server (Web sites
Computer or Web Server), use to communicate with each other. It
is used to transfer requests and files from one computer to another
via the Internet.
HTTP allows cross-platform documents, called hypertext
documents, to be located and accessed easily over the Internet.
These hypertext documents were viewable no matter which computer
platform you were using. This helped to derive the language HTML
- Hyper Text Markup Language. So HTTP is used to send HTML documents
through the Internet.
Documents and files on the Internet can be "downloaded"
or transferred from the Internet (webserver) to the client (users
computer). Applications (Programs) are the most common file type
that is downloaded from the Internet. Plug-Ins would be the second
most popular file type that is downloaded. Plug-Ins are snippets
of programs that will add additional functionality to existing programs.
An example would be Macromedia Shockwave, which allows the user
to view video and listen to audio files as well as to view animation
files.
One of the oldest and still one of the most popular
ways to transfer data or documents is the use of FTP - File Transfer
Protocol. Files or programs that are available for download are
usually placed on the FTP Server portion of the webserver (ftp://
instead of http://). These files are usually accessed through a
Hyperlink, although specialized programs such as ws-ftp
can be used instead.
The structure of the Webserver is similar to the
hard drive of a PC. If you think of the hard drive as a group of
folders and files, then you have a good grasp of the structure of
the Webserver. For example, the Root directory of a hard drive on
a PC, is the C:/ (or C drive), and the Root folder on a webserver
is the web address or URL, example (https://www.angelfire.com/wizard2/webbuildingtutorial
is the root directory of this website.)
If there were an Images folder on C drive, you
would access it through the path:
C:/Images, and to access the Images folder on a specified website,
you would access it by: https://www.angelfire.com/wizard2/webbuildingtutorial/Images. |
