The Internet, DNS & The Cloud

Definition

The Internet is simply a
worldwide collection of computer networks.

It is a "network of networks".

Examiner's Eye

Never write that "the Internet is the World Wide Web". Examiners hate this! The Internet is the physical hardware infrastructure (the cables and routers connecting the globe). The World Wide Web (WWW) is merely the software collection of web pages that runs on top of the Internet.

Domain Name System (DNS)

The system consisting of multiple servers that converts user-friendly URLs (like google.com) into numerical IP addresses.

How it works:

Step 1: Request The user enters a URL into their browser. The browser asks the designated DNS server for the matching IP.
Step 2: Database Check The DNS checks its local database for a match between the URL and an IP address.
Step 3A: If Not Found If the DNS doesn't know it, the query is forwarded to a higher-level DNS server.
Step 3B: If Found The matching numerical IP address is returned back to the user's browser, allowing it to connect to the correct web server.

The DNS Trap

A very common trap! Do not write that a DNS "searches the internet for the website". It does NOT. It simply acts as a mapped directory translating a URL into an IP address.

The Cloud (Hosting)

Remote service provision accessed via the Internet (e.g. storage, software, processing). Hosting simply means servers providing services to clients.

Advantages

  • Accessible from anywhere with an internet connection.
  • Easy to immediately scale storage up or down.
  • Backups, security, and hardware maintenance are managed automatically by the host company.

Disadvantages

  • Completely reliant on having a stable internet connection.
  • Susceptible to external hacking of the host's servers.
  • You hand over physical control of your private data to a third-party company.

The Cloud Security Trap

Do not say the Cloud is "easier to hack". Cloud servers often have enterprise-grade security. Instead, say "You are reliant on a third party to manage the security" or "Data could be intercepted while travelling over the internet".

Check Your Understanding

1. Why is a Domain Name System (DNS) server essential for human users browsing the internet?

2. What happens if a local DNS server cannot find the requested URL in its own database?

3. Which of the following is a significant drawback of relying on Cloud storage for a company's database?

Stretch & Challenge (AO2 Application)

Written Exam Scenario (AO2/AO3)

1 / 3

...

Previous: Hardware Next: Topologies