The Internet as a global network

The Internet connects computers and devices worldwide, enabling communication and data sharing on a massive scale. It functions as a wide area network (WAN) that links smaller networks together, allowing information to flow between them seamlessly.

Key features of the Internet

• Network of networks - The Internet is built from interconnected local and wide area networks, creating a global system where devices from different locations can communicate.
• TCP/IP protocol - This is the standard set of rules that governs how data is transmitted across the Internet. TCP (Transmission Control Protocol) handles the breaking down and reassembling of data packets, while IP (Internet Protocol) manages the addressing and routing of those packets to their destinations.

The World Wide Web and client-server model

The World Wide Web (WWW) is a key service available over the Internet, consisting of interconnected web pages and resources that users can access.

What is the World Wide Web?

• The WWW is a vast collection of websites stored on web servers around the world.
• It uses the HTTP (Hypertext Transfer Protocol) or HTTPS (a secure version) to transfer web pages and data between servers and user devices.

Client-server network in the WWW

• The WWW operates as a client-server network, where client devices (such as computers or smartphones) request information from servers.
• Servers host and provide the requested data, while clients receive and display it.

URLs and their structure

Uniform Resource Locators (URLs) act as addresses for locating specific resources on the Internet, such as web pages or files.

Components of a URL

A typical URL, like https://www.example.co.uk/path/to/page, breaks down into several parts:

• Protocol - This specifies the method for accessing the resource, such as https for secure connections or http for standard ones.
• Domain name - This is the human-readable address of the website, like www.example.co.uk, which identifies the server hosting the content.
• Path - This indicates the specific location of the file or page on the server, such as /path/to/page.

Domain Name System for address translation

The Domain Name System (DNS) simplifies web access by converting easy-to-remember domain names into the numerical IP addresses that computers use to locate servers.

How DNS works

• DNS is a distributed network of servers that store records linking domain names to their corresponding IP addresses.
• When you enter a domain name in a browser, your device queries a DNS server to find the matching IP address.
• This process eliminates the need to memorise complex IP addresses, making the Internet more user-friendly.

Cloud computing and hosting services

Cloud computing extends the capabilities of the Internet by providing remote access to storage, software, and processing resources.

What is hosting?

Hosting involves one organisation using its servers to store and manage files or applications for another organisation or individual. Traditionally, this is used for websites, where web servers store site files and make them accessible over the Internet.

Understanding cloud computing

Cloud computing, often just called 'the cloud', allows users to access data storage, applications, and computing power remotely via the Internet. It functions like an expanded client-server network, where user data is stored centrally on remote servers rather than local devices.

Key features of cloud computing:

• Providers often charge a subscription fee for full access, though some use a 'freemium' model, offering basic features for free with options to upgrade to premium services for a fee.
• Applications can run directly on powerful cloud servers, enabling users with basic hardware to handle complex tasks.
• The cloud also boosts computing power by distributing tasks across multiple servers, supporting memory-intensive operations beyond what a single device could manage.

Advantages of cloud computing

Cloud computing offers several benefits, making it a popular choice for individuals and businesses.

Key advantages

• Accessibility - Files and applications can be accessed from any device with an Internet connection, supporting flexible working.
• Scalability - Storage capacity can be easily expanded without purchasing new hardware.
• Cost savings - There is no need for expensive local hardware or IT staff to maintain it.
• Security and maintenance - Providers handle security measures, regular backups, and automatic software updates.

Disadvantages of cloud computing

Despite its benefits, cloud computing has drawbacks that users should consider.

Key disadvantages

• Internet dependency - A stable connection is required to access files or run applications; without it, resources are unavailable.
• Reliance on providers - Users depend on the host for security and backups, which could fail if the provider experiences issues.
• Security risks - Data stored remotely may be vulnerable to cyberattacks or unauthorised access.
• Ownership concerns - It can be unclear who legally owns data stored in the cloud, potentially leading to disputes.
• Ongoing costs - Subscription fees for storage and services can add up over time, especially for heavy users.