Introducing the Internet buzz words
World Wide Web
WWW is a part of the Internet which functions using HTML. WWW operates under a protocol called HTTP.
Browser
A browser is a computer software which can be used to view documents on the Internet. Web browsers interpret HTML code and display images and text.
Search Engine.Search engine is an automated web-site which is programmed to search specified keywords and give the websites and Internet based documents as a result.
Сlient.A computer which is capable of receiving the information from the server in the Internet is called a client. A home PC is an ideal example for this.
Server.Client computers download files in the Internet from the Server. These servers are directly linked to the internet and consist of a lot of documents.
Domain
The Domain is the top level identification string for a particular server (yahoo.com). There are various types of domains. It can be categorized using one or more extensions.
FTP
FTP is a standard Internet protocol which refers to the File Transfer Protocol. Using this protocol we can transfer files from one computer to the other via Internet. This is the simplest way to exchange files between computers on the Internet. FTP is an application protocol that uses the Internet's TCP/IP protocols. FTP is commonly used to transfer Web page files from their creator to the computer that acts as their server for everyone on the Internet. It's also commonly used to download programs and other files to your computer from other servers.
HTML
HTML is the abbreviation for Hyper Text Markup Language. The web pages are called hypertext documents because when you click a word or a picture which is hyper linked you can go to another location. From there you can jump to another webpage. This is made possible because HTML allows the document‟s author to embed hyperlinks.
HTTP
HTTP is the foundation of data communication for the World Wide Web. HTTP (Hypertext Transfer Protocol) is the set of rules for transferring files (text, graphic images, sound, video, and other multimedia files) on the World Wide Web. When the browser user enters file requests by either "opening" a Web file (typing in a Uniform Resource Locator or URL) or clicking on a hypertext link, the browser builds an HTTP request and sends it to the Internet Protocol address (IP address) indicated by the URL. The HTTP daemon in the destination server machine receives the request and sends back the requested file or files associated with the request.
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Example URL: http://www.yahoo.com
HTTPS
HTTPS stands for “Hyper Text Transfer Protocol Secure”. This means that the data transferred electronically is encrypted and cannot be accessed by unauthorized people. HTTPS provides authentication of the web-site and related web server which is interacting with thus protecting against Man-in-the middle attacks.
CSS
1. Short for Cascading Style Sheet, CSS is a concept first created by HåkonWium Lie in 1994. In December 1996, CSS was made a specification by the W3C and today allows web developers to alter the layout and appearance of their web pages. For example, CSS may be used to change the font used in certain HTML element, as well as its size and color. A single CSS file may be linked to multiple pages, which allows a developer to change the appearance of all the pages at the same time.
3. E-mail. Message format.
A person can exchange his/her messages digitally through e-mail. E-mail has so many similarities with the postal mail. Similar to a postal mail, e-mail too can be sent from anyone but the mail will be received by the person who owns a particular e-mail address. Of course, you would have used e-mail to convey messages to a person living in another part of the world.
How e-mail works in brief
The mails you send will be temporarily saved in your mail server. Email servers accept, forward, deliver, and store messages. Neither the users nor their computers are required to be online simultaneously; they need connect only to an e-mail server, to send or receive messages. Mail serveris also used to mean a computer acting as a Mail Transfer Agent (MTA) that isrunning the appropriate software.
Using emails
Email address.An Email address has 3 parts in it. If we type an email address, it will be in the following format.
Eg: username@hostname
1:-The first part identifies the user. Usually case sensitive. 2:- The @ sign which comes in between
E-mail address breakdown
support@computerhope.com
· The first portion all e-mail addresses, the part before the @ symbol, contains the alias, user, group, or department of a company. In our above example support is the Technical Support department at Computer Hope.
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· Next, the @ (at sign) is used as a divider in the e-mail address;
· E-mail clients
· An email client is a computer program used to access and manage a user's email. It is also referred to as an e-mail reader or a Mail user Agent (MUA). It can refer to any system capable of accessing the user's email mailbox, regardless of it being a mail user agent, a relaying server, or a human typing on a terminal. In addition, a web application that provides message
4. SMTP, POP3, IMAP protocols.
More about E-mailing concepts
The SMTP Server
When we send an email, our computer connects to our email service‟s mail server. A server is a centralized computer which manages a specific type of service. An email server for instance, handles emails. The email server responsible for sending emails is called the SMTP (Simple Mail Transfer Protocol) server. One SMTP server can pass on the mail to another SMTP server and relay it to the destination through several hops.
Every email has the sender‟s address (e.g. sender@sendermail.com) and the recipient‟s in the To
Field (e.g. recipient@recipientmail.com). When an email is sent, the email client connects to the
SMTP server of the sender‟s email service (e.g. mailserver.sendermail.com). The client transmits the address of the sender, the address of the recipient and the content of the message.
The SMTP server goes to work at locating the whereabouts of the recipient. Using the recipient‟smail ID(i.e. recipient@recipientmail.com) it locates the domain name–e.g.recipientmail.com.
Each domain name represents a unique Web address, called an Internet protocol (IP) address. Think of it as postal addresses of the internet. The link between domain names to their IP addresses is stored in the Domain Name Registry. The SMTP server then contacts the server where the registry is kept (The DNS Server). The DNS server sends back the address to the SMTP server.
The SMTP server then proceeds to hand over the email to the SMTP server of the recipient‟s email service (let‟s call it mailserver.recipientmail.com). This SMTP server checks and confirms that the mail addressed to recipient@recipientmail.com belongs to it and hands it over to its counterpart, the POP3 server (or the IMAP server).
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The POP3 Server
Post Office Protocol (POP3)servers are the servers that do the job of receiving mails. The number ‘3’ is the version number of the protocol in use. POP3 servers have mail accounts (our email IDs). Each mail account is mapped to a username-password combination. Once the message is handed over to the POP3 server, it is kept and stored in the mail account till the recipient logs in and checks the mail.
The IMAP Server
An email client connects to the POP3 server and tells it to allow download of the email. Once downloaded to the local machine, POP3 mailboxes do not retain a copy of the email. Thus, you cannot check your emails from another PC as it has already been downloaded. To tack this difficulty, IMAP was introduced. IMAP (Internet Message Access Protocol version) simply retains a copy of the emails on the server. This allows you to access your e-mail from any location with an internet connection.
Questions:
1. What is a „mail server‟? Describe how to send an e-mail between two people.
2. What is an e-mail client? Name two types of e-mail clients with examples.
3. Definethefollowingterms.
SMTP
DNS Server
4. What are the advantages of POP sever and IMAP server?
5. When sending an e-mail what is the difference between CC and BCC?
6. How can you attach a document to your e-mail?
7. List three e-mail etiquettes and give reasons for doing them.
8. What are the three parts of an e-mail address?
9. When creating an e-mail account what is the purpose of typing a given code in the cage provided?
10. What is the purpose of “inbox” in an e-mail account?
References
1. June J. Parsons and Dan Oja, New Perspectives on Computer Concepts 16th Edition - Comprehensive, Thomson Course Technology, a division of Thomson Learning, Inc Cambridge, MA, COPYRIGHT © 2014.
2. Lorenzo Cantoni (University of Lugano, Switzerland) James A. Danowski (University of Illinois at Chicago, IL, USA) Communication and Technology, 576 pages.
3. Craig Van Slyke Information Communication Technologies: Concepts, Methodologies, Tools, and Applications (6 Volumes). ISBN13: 9781599049496, 2008, Pages: 4288
4. Utelbaeva A.K.,Utelbaeva A.K. Study guide for lectures on discipline “Computer science”, Shimkent 2008, 84 pages.
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