In this article
Typing an address and pressing Enter feels instant. Behind that moment is a chain of steps involving computers spread across the world. Understanding it helps explain why sites are sometimes slow, what the padlock icon means and why one fault can take many websites offline at once.
Key facts
- DNS works like a phone book, turning names such as worldelev.com into numerical addresses.
- Root servers: 12 organizations run the system’s top level, through more than 2,000 server copies worldwide.
- HTTPS encrypts the connection and proves the site is who it claims to be.
- One page can require dozens of separate files: text, styles, fonts, images and scripts.
Step 1: Finding the address (DNS)
Computers find each other using numerical IP addresses, not names. The Domain Name System (DNS) translates names into numbers.
- Your device first checks whether it already knows the answer from a recent visit.
- If not, it asks a resolver, usually run by your internet provider or a public service.
- If the resolver does not know, it starts at the top: a root server points it to the servers for “.com”, which point it to the servers that hold the records for the specific website.
- The answer comes back and is stored for a while, so the next visit is faster.
The root of this system is run by 12 independent organizations. According to root-servers.org, they operated 2,045 server instances around the world in September 2026, which is why the system rarely fails.
Step 2: A secure connection (HTTPS)
Next your browser connects to the website’s server. On most sites today it sets up an encrypted HTTPS connection. Two things happen:
- Identity check: the server shows a digital certificate issued by a trusted authority. Your browser checks it matches the site’s name. This is what the padlock means: the connection is private and the site is genuine, not that the site’s owners are trustworthy.
- Encryption: the two sides agree on keys so that anyone watching the network sees only scrambled data.
If the certificate does not match, your browser shows a warning. Never ignore it on a site where you enter passwords or payment details; it can be a sign of an attack of the kind described in our guide to spotting phishing.
How to Recognize a Phishing Email Before You Click
Step 3: Requesting and building the page
The browser asks the server for the page. The server replies with HTML, a text file describing the page’s structure. The HTML refers to other files the browser must fetch:
| File type | What it does |
|---|---|
| HTML | The structure and text of the page |
| CSS | Colors, fonts, spacing and layout |
| JavaScript | Interactive features such as menus and forms |
| Images and video | Pictures and media |
| Fonts | The typefaces the design uses |
Modern browsers fetch many of these in parallel and start drawing the page before everything has arrived, so text often appears before images.
Why pages are sometimes slow
- Distance: data travelling to a server on another continent takes longer. Many sites use content delivery networks that keep copies closer to visitors.
- Page weight: large images and heavy scripts take longer to download, especially on mobile.
- Busy servers: a sudden spike in visitors can overwhelm a site.
- Shared failures: if a major DNS or hosting provider has a fault, thousands of unrelated websites can go down together.
What you can do
- Keep your browser and operating system updated; our article on why software updates matter explains why.
- Check the address bar before typing passwords, and never click through certificate warnings on important sites.
- If only one site fails to load, the problem is probably at the site’s end; if all sites fail, check your own connection.
How long each step takes
| Step | Typical time |
|---|---|
| DNS lookup (if not already stored) | A few to a few hundred milliseconds |
| Setting up a secure connection | Tens of milliseconds, more on distant servers |
| Downloading the page and its files | From under a second to several seconds, depending on page size and connection |
Frequently asked questions
What is an IP address?
A numerical label that identifies a device on a network, such as 192.0.2.1 in the older IPv4 format or a longer string in the newer IPv6 format. DNS exists so that people can use names instead.
Does the padlock mean a website is safe?
It means the connection is encrypted and the site’s identity has been verified for its name. Criminals can also get certificates for look-alike names, so check the address itself carefully.
Why does clearing my cache sometimes fix a website?
Your browser stores copies of files to load pages faster. If a stored copy is out of date or damaged, clearing it forces the browser to download fresh versions.
