Blog 3 Internet and Web Applications

Good day to you! Stay Safe Stay Healthy!!

By the end of this class, you will be able to :

- know the various aspects of URL and IP addresses, internal working strategy of an IP address

- understand the Internet and its applications

- know the various Web applications and their purpose

6. URL – Uniform Resource Locator, commonly known as a "web address".

A URL is human-readable text that was designed to replace the numbers (IP addresses) that computers use to communicate with servers. To correctly render in all browsers, URLs must be shorter than 2,083 characters.

URL consists of

·       a protocol,

·       domain name,

·       and path (which includes the specific subfolder structure where a page is located)

and has the following basic format -- >  protocol://domain-name.top-level-domain/path

Eg -          https://www.google.com/maps/dir/

URL Concept by Sir Tim Berners Lee - https://www.ietf.org/rfc/rfc1738.txt

URI

URI is an acronym for Uniform Resource Identifier, more commonly and incorrectly called a URL. A URL is a part of a URI (see the example below).

OR

IP Address – IP (Internet Protocol) Address is an address of your network hardware (any device which is active on a network). It helps in connecting your computer to other devices on your network and all over the world. An IP Address is made up of numbers or characters. These numbers are arranged in a particular pattern to identify the address of a device over a network perfectly (

The format of an IP address is – xxx.xxx.xxx.xxx

Where the xxx is the decimal number ranging from 0 to 255 (total 256)

Example – 8.8.8.4,       191.1.198.1 ,    121.111.160.1  etc.

This is called IPv4 (IP version 4) which gives you a possible combination of 4 billion numbers.

An IPv4 address consists of four numbers, each of which contains one to three digits, with a single dot (.) separating each number or set of digits. Each of the four numbers can range from 0 to 255.

An IPv6 address consists of eight groups of four hexadecimal digits. If a group consists of four zeros, the notation can be shortened using a colon to replace the zeros. Here's an example IPv6 address:

2001:0db8:85a3:0000:0000:8a2e:0370:7334

Domain Name System, or DNS. (Although many people think "DNS" stands for "Domain Name Server," it really stands for "Domain Name System.")

Its purpose is vital, as it helps convert easy-to-understand domain names like "howstuffworks.com" into an Internet Protocol (IP) address, such as 70.42.251.42 that computers use to identify each other on the network. It is, in short, a system of matching names with numbers.

Click to see IP working

Our computer's IP address come from a Dynamic Host Configuration Protocol (DHCP) server on your network. The job of a DHCP server is to make sure your computer has the IP address and other network configuration it needs whenever you're online. Because this is "dynamic," the IP address for your computer will probably change from time to time, such as when you shut down your computer for a few days.

Voice over Internet Protocol (VoIP)

is a technology that allows you to make voice calls using a broadband Internet connection instead of a regular (or analog) phone line.

VoIP services convert your voice into a digital signal that travels over the Internet. If you are calling a regular phone number, the signal is converted to a regular telephone signal before it reaches the destination. VoIP can allow you to make a call directly from a computer, a special VoIP phone, or a traditional phone connected to a special adapter. In addition, wireless "hot spots" in locations such as airports, parks, and cafes allow you to connect to the Internet and may enable you to use VoIP service wirelessly.

7. WWW

The World Wide Web (WWW), commonly known as the Web, is an information system where documents and other web resources are identified by Uniform Resource Locators which may be interlinked by hypertext, and are accessible over the Internet.

The resources of the WWW are transferred via the Hypertext Transfer Protocol (HTTP)

The resources may be accessed by users by a software application called a web browser 

The resources are published by a software application called a web server

Hypertext – text written in a specific code/ language which can navigate through various resources. (hyperlinks)

HTML – is the standard markup language for documents designed to be displayed in a web browser.

It can be assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScript.

HTML documents describes the structure of a web page which is received by the Web browsers  from a web server or from local storage and render the documents into multimedia web pages.

Web Applications

Web Application or web app is a computer program that utilizes web browsers and web technology to perform tasks over the Internet.

Web App is a client–server computer program that the client runs in a web browser. Common web applications include webmail (web-based free email accounts operated from a website like Hotmail, Gmail and Yahoo Mail needs an Internet connection and a web browser), online retail sales, online banking, and online auctions.

Web applications use a combination of server-side scripts (PHP - Hypertext Preprocessor or earlier - Personal Home Page, is a general-purpose programming language used to design a website or web applications, is embedded with HTML to develop Static website, Dynamic website or Web applications  and ASP - ASP is an abbreviation of Active Server Page. It is now has been supplanted by ASP.NET. It was developed by Microsoft and it was Microsoft's first server-side script engine to permit programmers to create and run a website and web server applications, which should be dynamic) to handle the storage and retrieval of the information, and client-side scripts (JavaScript and HTML) to present information to users. 

The web application requires a web server to manage requests from the client, an application server to perform the tasks requested, and sometimes a database to retrieve/store the information. 

Work Flow of Web Apps

1. User triggers a request to the web server over the Internet, either through a web browser or the application’s user interface    
2. Web server forwards this request to the appropriate web application server
3. Web application server performs the requested task – such as querying the database or processing the data – then generates the results of the requested data
4. Web application server sends results to the web server with the requested information or processed data
5. Web server responds back to the client with the requested information that then appears on the user’s display

Advantages of Web Apps

• Web applications run on multiple platforms regardless of OS or device as long as the browser is compatible
• All users access the same version, eliminating any compatibility issues
• They are not installed on the hard drive, thus eliminating space limitations
• They reduce software piracy in subscription-based web applications (i.e. SaaS)
• They reduce costs for both the business and end user as there is less support and maintenance required by the business and lower requirements for the end user’s computer

A server is a central repository where information and computer programs are held and accessed by the programmer within the network.

Web Server - is a computer program that accepts the request for data and sends the specified documents. Web server may be a computer where the online content is kept.

Examples – Apache Tomcat, Resin

Application server - organize the run atmosphere for enterprises applications. Application server may be a reasonably server that mean how to put operating system, hosting the applications and services for users, IT services and organizations. 

Examples of Application Server  -   Weblogic, JBoss, Websphere

Website

Introduction – Webpage is the smallest entity of a collection, whereas Website is the collection of such webpages.

Differences between a website and webpage

BASIS FOR COMPARISON	WEB PAGE	WEBSITE
Basic	Web page is a part of website which comprises links to other web pages.	Website is a cluster of related web pages addressed to a typical URL.
Presented by	Multiple web pages can have the same name if they reside in different documents.	By a unique URL.
Use	It is a content that is to be displayed on a website.	It is a place used to display the content.
Extension	The web page URL has an extension.	There is no extension used in the URL of a website.
Address dependency	Web page address depends on website address.	Website address doesn't rely upon web page address.
Development period	Requires less time to develop as it is a part of a website.	Usually, take more time as compared to a web page.

Static vs Dynamic web page

A static web page also called a flat page or a stationary page are HTML documents stored as files in the file system by the web server through HTTP.

Static web pages are suitable for the contents that never or rarely need to be updated.

Simply Static Web pages are very simple, written in languages such as HTML, JavaScript, CSS, etc.

For static web pages when a server receives a request for a web page, then the server sends the response to the client without doing any additional process. And these web pages are seen through a web browser.

In static web pages, pages will remain the same until someone changes it manually.

Dynamic Web Pages are written in languages such as CGI, AJAX, ASP, ASP.NET, etc. In dynamic web pages, the Content of pages is different for different visitors. It takes more time to load than the static web page. Dynamic web pages are used where the information is changed frequently, for example, stock prices, weather information, etc.

Hosting of a website           

Web hosting is a service that allows organizations and individuals to post a website or web page onto the Internet. A web host, or web hosting service provider, is a business that provides the technologies and services needed for the website or webpage to be viewed in the Internet. Websites are hosted, or stored, on special computers called servers. When Internet users want to view your website, all they need to do is type your website address or domain into their browser. Their computer will then connect to your server and your webpages will be delivered to them through the browser.

Most hosting companies require that you own your domain in order to host with them. If you do not have a domain, the hosting companies will help you purchase one.

Web hosts are companies that provide space on a server owned or leased for use by clients, as well as providing Internet connectivity, typically in a data center.

Web Browsers: Introduction

A web browser is a software application for accessing information on the World Wide Web. Web browsers are used on a range of devices, including desktops, laptops, tablets, and smartphones.

Common web browsers include Microsoft Internet Explorer, Google Chrome, Mozilla Firefox, and Apple Safari.

For example, Ajax enables a browser to dynamically update information on a webpage without the need to reload the page.

It’s a matter of statistics and realizing how impacting they are for your business. 

Web Browser Market Share:

·       Chrome. 55.2%

·       Safari. 13.5%

·       Internet Explorer & Edge. 6.1%

·       Firefox. 5.4%

·       Opera. 3.2%

Browser Settings

Every Internet browser has settings you can change, including privacy settings, search engine preferences, autofill and autocomplete behaviour, and more. To get instructions for changing the settings in your Internet browser, let say for example –

Google Chrome

 To access the settings menu in Google Chrome follow the steps below.1.    Open the Chrome browser.
2.    In the upper-right corner, click the Customize and Control 

          Google Chrome   icon              3.    Select the Settings entry in the menu.

Microsoft Edge 

      

                         To access the settings menu in Microsoft Edge follow the steps below.                                        1.  Open Microsoft Edge browser.
                              2.  In the upper-right corner, click the Customize and Control             
                                   Microsoft Edge icon 
                              3. Select the Settings entry in the menu.

           
          Mozilla Firefox 
                          
                        

                       To access the settings menu in Mozilla Firefox, follow the steps below.

                   1. Open the Firefox browser

                   2. In the upper-right corner, click the Open menu icon.

                   3. Select the Options entry in the menu

                 Safari 

                 

                        

                    To access the settings menu in Safari, follow the steps below.

               1. Open the Safari browser

               2. In the upper-left corner, click on Safari in the menu bar

              3. Select the Preferences entry in the menu

Add-ons & Plug-ins

Add-on is the Mozilla term for software modules that can be added to the Firefox web browser and related applications.

An add-on is a software extension that adds extra features to a program. It may extend certain functions within the program, add new items to the program's interface, or give the program additional capabilities.

For example, Mozilla Firefox, a popular Web browser, supports add-ons such as the Google toolbar, ad blockers, and Web developer tools.

Some computer games support add-ons that provide extra maps, new characters, or give the player game-editing capabilities.

There are three types: extensions, themes, and plug-ins. Mozilla hosts them on its official add-on website.

Plug-ins – are software for web browsers which enhances the functionality of a web browser.

A browser plug-in (such as Macromedia Flash or Apple QuickTime) allows you to play certain multimedia files within your Web browser.

Most graphics and audio programs today support plug-ins since they are a convenient way to expand the capabilities of the program.

These plug-ins are usually available as free downloads from the Internet.

Cookies

A cookie is a small amount of data generated by a website and saved by your web browser. Its purpose is to remember information about you, similar to a preference file created by a software application.

Functions of Cookies –

1. To store login information for a specific site. Some sites will save both the username and password in a cookie, while others will only save your username.

2.  Cookies are also used to store user preferences for a specific site.

For example, a search engine may store your search settings in a cookie. A news website may use a cookie to save a custom text size you select for viewing news articles. Financial websites sometimes use cookies to store recently viewed stock quotes. 

Browser cookies come in two different flavours: "session" and "persistent"

Session cookies are temporary and are deleted when the browser is closed.

These types of cookies are often used by e-commerce sites to store items placed in your shopping cart, and can serve many other purposes as well.

Persistent cookies are designed to store data for an extended period of time.

Each persistent cookie is created with an expiration date, which may be anywhere from a few days to several years in the future. Once the expiration date is reached, the cookie is automatically deleted.

E-mail

Short for electronic mail, e-mail or email is information stored on a computer that is exchanged between two users over telecommunications. More plainly, e-mail is a message that may contain text, files, images, or other attachments sent through a network to a specified individual or group of individuals.

The first e-mail was sent by Ray Tomlinson in 1971. Tomlinson sent the e-mail to himself as a test e-mail message, containing the text "something like QWERTYUIOP." 

E-mail address breakdown

myname@organization.topleveldomain OR   support@computerhope.com

·       The first portion of 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.

·       Next, the @ (at sign) is a divider in the e-mail address; it's required for all SMTP e-mail addresses since the first message was sent by Ray Tomlinson.

·       Finally, computerhope.com is the domain name to which the user belongs. The .com is the TLD (top-level domain) for our domain.

Advantages of e-mail

Free delivery , Global delivery, Instant delivery, File attachment , Long-term storage , Environmentally friendly.

Webmail are web-based email accounts. These are usually free email accounts that are operated from a website. Examples include Hotmail, Gmail and Yahoo Mail. 

Webmail allows the users to access their emails as long as they have access to an Internet connection and a web browser.

Differences between web mail and email

web mail	e-mail
Web mail are hosted in the cloud. The cloud service will automatically synchronize your e-mail to all your devices, including your desktop, computer, tablet, smartphone.	an e-mail client requires the user to install software directly onto their computer; if the software is not installed, e-mail may not be accessed.
is a free service	many e-mail clients cost money
	generally more secure since not over cloud
	notifications pop up easily
Gmail maintains a limited add because of its advanced settings features.	Adds limited
Eg.- Gmail, Hotmail, Yahoomail, Rediffmail	Eg – Microsoft Outlook, Mozilla Thunderbird, DreamMail, Mail for Windows 10, eM Client.

 You may Raise your doubts through Comment.

Thank you!!! Stay safe stay healthy!