Networking · Visually explained
See What Happens When
You Open a Website.
Follow what happens after you enter a web address—from DNS and local networking to secure transport, HTTP responses, and browser rendering.
Follow the journey ↓Today’s mission
Open a website and watch the trip.
When you enter a site name, the browser needs a destination IP address before it can start a new connection to that site. It first checks for a reusable address; otherwise it asks a DNS resolver.
- 01Enter a nameYou request example.com.
- 02Resolve it with DNSCache or resolver supplies an IP address.
- 03Connect securelyTCP with TLS, or QUIC, prepares transport.
- 04Request the pageHTTP asks for the document and resources.
- 05Process responsesThe browser receives and parses data.
- 06Render progressivelyContent becomes visible as work completes.
DNS happens before a new site connection: DNS means Domain Name System. Its query and answer are themselves packets that cross local links and routed networks. Chapters 1–6 unpack these foundations; Chapter 7 puts the browser events back into chronological order.
After an IP address is known
Packets cross the network in both directions.
Ready. The browser needs an IP address before it can start the website connection.
Teaching model: this line shows one HTTP exchange after address resolution. DNS queries also travel through network devices, routes can differ in each direction, and real pages make many requests.
Chapter 01 / 08
Hello, Network!
Goal: Understand how connected devices exchange the information used throughout a website visit.
A network is a group of connected devices that can exchange information. The connection might use a cable, Wi-Fi radio waves, or several joined links. When you open a website, your browser exchanges messages with a server through local equipment and other networks.
TakeawayA browser sends requests across networks, and a server sends responses back.
Ready. The browser will send a request and the server will return a response.
Chapter 02 / 08
Meet the Neighborhood
Goal: See how your device reaches the first router.
An access point is the Wi-Fi radio your device joins. A gateway sends traffic from your local network to other networks. Home equipment often combines both jobs in one box.
TakeawayYour device uses a local link to reach its gateway.
Wi-Fi selected. Send data to see it cross the local link and gateway.
Chapter 03 / 08
Message, Meet Pieces
Goal: See why data travels in smaller pieces.
IP networks carry data in packets; on Wi-Fi or Ethernet, an IP packet rides inside a local-link frame. IP is best effort and does not recover every missing packet. When an application needs reliability, a transport such as TCP or QUIC can detect missing data, retransmit it, and deliver it in the required order.
Teaching model: the numbered letters below represent ordered application data carried by a reliable transport and IP. Real packets normally carry many bytes plus protocol headers—not one letter each.
All seven teaching pieces rebuild NETWORK.
Chapter 04 / 08
DNS: The Internet’s Name Game
Goal: See how the browser finds a destination address before opening a new site connection.
DNS—the Domain Name System—maps names people use to IP addresses networks can route toward. After you enter a site name, the browser and operating system check for a usable cached answer. If none is available, the device sends a DNS query to its configured resolver. The resolver can answer from its cache or perform more DNS lookups.
Where it happensAddress resolution happens before a new connection to the website. The DNS query and answer themselves use packets, local links, and routing.
google.com→No cached answer is shown. Run DNS before contacting the website.
Chapter 05 / 08
Pick a Path
Goal: See how routers move a packet one step at a time.
Each router reads the destination IP address and chooses a next hop using its current routing information. After a failure, routing needs time to converge on another available path.
TakeawayNo router needs to know the entire physical journey.
Teaching model: each branch represents a simplified sequence of router hops, not one router. Real routing recovery varies by protocol, configuration, and failure, and the return path may differ.
The device sends to its gateway; traffic then crosses the simplified primary multi-hop path.
Chapter 06 / 08
Secure Web Delivery: TCP + TLS and QUIC
Goal: Compare secure web transport over TCP and QUIC.
TCP provides a reliable, ordered byte stream. Web traffic commonly secures TCP with TLS. QUIC runs over UDP and integrates TLS 1.3 with its transport handshake while providing reliable delivery and independent streams. HTTP/3 uses QUIC; HTTP/1.1 and HTTP/2 commonly use TCP with TLS.
What about plain UDP?
UDP itself is a small, connectionless transport. An application can value timeliness over recovery or build additional behavior on top—as QUIC does.
Chapter 07 / 08
Open Sesame, Website!
Goal: Put the earlier concepts into the real order of a fresh website visit.
This is the chronological workflow. After you enter a name, a usable cached DNS answer can supply its IP address immediately; otherwise the device asks a DNS resolver. The browser can then create or reuse a secure connection, exchange HTTP data, process resources, and render progressively.
Keep in mindPackets cross the local link and routed path during DNS, connection setup, and HTTP. Packetization and routing are continuous foundations, not one-time stages.
Complete journey playback
Follow the browser from name to rendered page.
Stage 1 of 7
Enter the site name
The browser receives the name of the site you want to open.
- Where
- Your browser
- Why it matters
- The browser needs to know which site you want.
Chapter 08 / 08
The Feel of Fast
Goal: See how network conditions shape modeled request and transfer time.
Run a simplified network-time model, then change one condition at a time. The numbers teach relationships; they do not predict a complete page load.
Model boundary: an 800 KB response, a new secure connection, one responsive DNS resolver, and a working alternate path. The loss penalty is an illustrative approximation, route recovery is your selected assumption, and jitter is reported without inventing a fixed penalty. Server processing, protocol overhead, congestion control, slow start, resource discovery, parsing, and rendering are excluded.
Journey complete