The Internet & The World Wide Web

The Internet

The Internet is a global network of networks consisting of billions of computers and other devices connected all around the world. These devices are connected wires, fibre-optic cables, microwave links and wireless satellites.

Not just computers, the Internet also consists of external sensors and devices such as TVs, cars, household appliances and security cameras. Collectively, these devices are known as the Internet of Things.

World Wide Web

The World Wide Web is a network of connected files hosted over the Internet. These include web pages, pictures, sounds and videos. These are all connected using hyperlinks. It was invented in 1989 by Sir Tim Berners-Lee. He created a method of putting websites onto the internet. Collectively, these websites are known as the World Wide Web.

The Web is like a large collection of documents with links to each other, the documents being web pages.

Internet Terms

HTML:

The Hypertext Markup Language or HTML is the standard markup language for documents designed to be displayed in a web browser. It is often assisted by technologies such as Cascading Style Sheets (CSS).

Web Browser:

A web browser is an application for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's screen.

URL:

URL is an acronym for Uniform Resource Locator and is a reference (an address) to a resource on the Internet, such as web page.

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The Internet & The World Wide Web

Repeaters receive data and re-transmit it. Repeaters are often used in fiber-optic cables to boost signal strength for data transmission over long distances.

Client-Server Model

Whenever you visit a web page, your computer is acting as a client and is requesting information, which is then provided by the server. This information is then displayed to the user in the form of a web page by a web browser.

If too many clients try to request information from a server, it may slow down or crash. A notorious example of this is Ticketmaster, whose servers can rarely cope with the high demand seen for concert tickets.

Communication Protocols

Protocols are rules and procedures for network communication. They are an agreed way to communicate between two devices such as computers.

Different protocols are used are different layers of the network. All of these layers and protocols are required in order for the Client-Server model to work.

• Application – HTTP/HTTPS
• Transport – TCP
• Network – IP
• Physical - Wi-Fi

HTTP

HTTP stands for Hypertext Transfer Protocol. It allows a client to issue a request for a resource such as a webpage and then allows the server to respond with that requested information. HTTP is a protocol specific to applications including web browsers and web server hosting software.

HTTPS

HTTPS stands for Hypertext Transfer Protocol Secure and is, as the name suggests, a secure version of HTTPS. It automatically encrypts data that is being transmitted meaning that hackers attempting to intercept the information cannot decode it. HTTPS is the standard for most websites and is denoted by a lock next to the URL.

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The Internet & The World Wide Web

TCP

TCP stands for Transmission Control Protocol. It operates at the transfer layer of a network and ensures that binary information is reliably transferred between computers. TCP breaks the information up into packets to allow for efficient routing. TCP keeps track of these packets and ensures that they arrive at the client in the same order they left the server.

IP

IP stands for Internet Protocol and operates at the network layer. IP handles the creation of data packets and routes them to their destination.

It does this using an IP Address, a unique code that identifies a computer or a particular device on that network. IP ensures that the correct address is attached to every packet coming from the server and reaches the correct client.

Wi-Fi

Wi-Fi is a radio wave technology that allows electronic devices such as phones and laptops to communicate with each other and access the Internet wirelessly. It operates at the physical layer and manages the flow of data around Wi-Fi networks.

VOIP

VOIP stands for Voice Over Internet Protocol. It is not actually a single protocol but a number of methods that are used together in order to deliver voice data over the internet. Facetime, WhatsApp and Microsoft Teams all use VOIP methods.

Cloud Computing

Cloud computing refers to the processing, storing and accessing of data over the Internet on specially designed servers. The data is normally stored on cloud services such as OneDrive, Google Drive or iCloud. Customers only need to pay for as much storage as they require. This elasticity is one of the key benefits of cloud computing.

Other benefits include the ability to easily share files, access files remotely from any location and always having the most up to date software. Possible risks of cloud computing include the data being prone to hacking and requiring a constant internet connection to access the data.

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The Internet & The World Wide Web

Advantages of Cloud Computing

• No need to for one-off up-front capital costs.
• Economies of scale meaning that cloud providers can offer shared services more efficiently thereby reducing carbon footprint.
• Cloud providers offer backup and disaster recovery features. Storing data in the cloud rather than locally can help prevent data loss in the event of an emergency, such as hardware malfunction, malicious threats, or even simple user error.

Disadvantages of Cloud Computing

• Costs are ongoing (pay-as-you-go) which could work out more expensive in the long run.
• Owing to its success there is a greater demand for cloud services – thus increasing the energy demand and greater carbon footprint.
• The nature of cloud computing makes it vulnerable to server downtime. During downtime, customers are forced to wait until the connection is restored before they can access the service. Depending on how long the downtime lasts, this situation can cause critical damage to businesses.