Module 05 · Section 1.3.1
The Internet & DNS
1
User types a URL
The user types a human-readable URL (e.g.
www.ocr.org.uk) into their browser. The computer needs the IP address to locate the server.2
URL sent to DNS Server
The browser sends the URL to the DNS (Domain Name System) Server. The DNS acts as a directory mapping website names to their IP addresses.
3
DNS looks up the IP address
The DNS server searches its database/table for the URL. It finds the corresponding IP address (e.g.
216.58.201.36).4
IP address returned to browser
The DNS server returns the IP address back to the user's browser. Translation is complete.
5
Browser contacts the Web Server
Using the IP address, the browser sends an HTTP/HTTPS request directly to the web server.
The Internet vs The World Wide Web
The Internet is the global network of hardware. The WWW is just one service (web pages) that runs on it.
The Internet is the global network of hardware. The WWW is just one service (web pages) that runs on it.
⚠ Examiner Warning: DNS is a DIRECTORY, not a Search Engine
A DNS does not "search the internet for the website". It simply looks up a URL in a database/table. It is a translation service.
Step 1 of 5
Step 1: Browser has a URL — needs an IP address