Internet Basics: IP Addresses, DNS and HTTPS Explained
Learn what happens when you open a website, how IP addresses, DNS and HTTPS work, and how to investigate common connection problems.
Opening a website involves several different systems. Understanding the role of each one helps you learn web development and describe connection problems more clearly. Start with the journey from a device to a page, then try the small observation exercise below.
Learn the terms by the job they do
| Term | Role | Useful distinction |
|---|---|---|
| Wi-Fi | Connects your device wirelessly to a local network | A strong signal does not prove the internet connection works |
| Router | Moves traffic between networks | A home router often combines routing, Wi-Fi and other functions |
| IP address | Addresses a network interface so traffic can be routed | It is not a permanent identity for a person |
| DNS | Resolves names through records, including address records | A website name may lead to multiple addresses |
| HTTP | Defines web requests and responses | A working connection can still return an error response |
| HTTPS | Protects HTTP traffic using TLS | Encryption does not prove that a site’s claims are trustworthy |
What happens when you open a website?
The browser interprets the address and may use cached information to resolve the hostname. DNS helps find the service’s network address. The browser then establishes a connection and, for HTTPS, negotiates a protected connection and checks the certificate.
It sends a request for a resource. The server returns a response, which includes a status code and may include HTML. As the browser processes the document, it can request stylesheets, scripts, fonts and images. It combines these resources into the page you see.
This is a simplified route: caches, redirects, service workers and content delivery networks can change where requests go or whether a new network request is needed. See MDN’s introduction to how the web works for the basic request journey.
Read a URL one piece at a time
https://example.com/lessons?topic=networking#practicehttps is the scheme; example.com is the hostname; /lessons is the path. The query string contains topic=networking. The fragment #practice can identify a location within a document and is not sent as part of the HTTP request target.
Pay attention to the actual hostname when checking a link. A familiar brand appearing in the path or query does not make that brand the site owner. For example, example.com/bank-name is still a page on example.com.
Exercise: watch a page load
- Open a public information page that does not require signing in.
- Open the browser’s developer tools and choose the Network panel.
- Reload the page and look for the main document request.
- Inspect its status, content type and timing, then compare it with an image request.
- Reload again and look for resources served from a cache.
You should usually see more than one request because a page is made from several resources. The precise timings and addresses will vary. A cached resource may not need a full download, so two reloads need not transfer the same amount of data.
Do not share an unedited network export from a signed-in session. Request headers and URLs can contain tokens or personal information. This exercise only requires observing a public page.
Separate connection problems from website problems
If one page fails, first try another page on that site and an unrelated site. Then compare another device on the same network. These observations narrow the problem without immediately changing router settings.
| Observation | Next check |
|---|---|
| Only one browser fails | Check its extensions, proxy settings and a private window |
| All devices lose internet access | Check the router’s WAN status and whether the provider reports an outage |
| A name-resolution error appears | Verify the hostname and check whether other names resolve |
| The server returns 404 | Check the path; the requested resource was not found |
| The server returns a 5xx status | The response reports a server-side failure; repeated local resets may not help |
Record the exact message and time before changing anything. A screenshot with private details removed is more useful to support than “the internet is broken.” For home wireless issues, continue with our Wi-Fi troubleshooting guide.
Check your understanding
Can Wi-Fi work while the internet is down?
Yes. Your device may still communicate with a local printer or router even when the connection to your internet provider is unavailable.
Does HTTPS mean a website is safe to buy from?
No. It protects the connection to the named site. A deceptive site can also use HTTPS, so check the identity, reputation and transaction details separately.
Will changing DNS always make downloads faster?
No. Name resolution is only one part of reaching a service. Wi-Fi quality, provider capacity, server load and other factors affect transfer performance.
Sources and further reading
Consult the linked documentation for details and version-specific requirements. The exercises are designed for learning; results can vary with your browser and environment.
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