How Websites Work: Client, Server, HTTP and the Browser
Basics3 minInnovialabs editorial team
In short
A website is a conversation: the browser (client) finds the server through DNS, sends an HTTP request, and the server returns HTML, CSS, JavaScript and data that the browser turns into a page.
The short answer: a request and a response
Every website follows the client-server model. The client is your browser (or a mobile app). The server is a computer in a data center that stores the site's code and data. They talk over HTTP: the client sends a request, the server sends back a response.
Everything else — DNS, databases, CSS, JavaScript — exists to make that conversation fast, good-looking and useful.
The players and their roles
| Player | What it does |
|---|---|
| Browser | Sends requests, receives files and draws the page |
| DNS | Translates a domain name (like example.com) into the server's IP address |
| Server | Accepts requests, runs code, returns responses |
| Application (backend) | Site logic: sign-in, orders, calculations |
| Database | Stores users, products, leads and anything that changes |
The whole journey in one diagram
[You] --type an address--> [Browser]
|
| 1. "What is the IP of example.com?"
v
[DNS] --> 203.0.113.10
|
| 2. HTTP request: GET /catalog
v
[Server] --3. query--> [Database]
| <--4. products--
| 5. HTTP response: 200 OK + HTML
v
[Browser] --6. loads CSS, JS, images
|
v
[Finished page]
What an HTTP request and response are
A request contains a method, an address and headers. The most common methods:
- GET — fetch data (open a page, load an image);
- POST — send data (a contact form, a payment);
- PUT/PATCH and DELETE — change or remove data, usually through an API.
A response contains a status code and a body. Codes worth knowing:
- 200 — everything is fine;
- 301/302 — the page moved, the browser follows the new address;
- 404 — the page does not exist;
- 500 — something broke on the server.
Almost every site today uses HTTPS — the same HTTP inside an encrypted channel. Without it, browsers mark the site as not secure.
Where HTML, CSS, JavaScript and the database live
- HTML — the structure and content of the page: headings, text, links, forms.
- CSS — the look: colors, fonts, layout, mobile adaptation.
- JavaScript — the behavior: menus, sliders, sending forms without reloading.
These three run in the browser — that is the frontend. The code on the server that decides what to send and works with the database is the backend. Users never see the database directly, only what the server chooses to show.
Static vs dynamic websites
- Static — the server returns ready-made files. Fast, cheap to host, great for landing pages and blogs.
- Dynamic — the page is assembled at request time from database data. Needed for user accounts, online stores, CRMs.
Modern frameworks often mix both: some pages are generated in advance, others on demand.
Common misconceptions
- "The site is stored in the browser." No, the browser only caches files temporarily; the original lives on the server.
- "A domain and hosting are the same thing." A domain is a name, hosting is where the server runs. DNS connects the two.
- "If the page opens, the server is fine." The page may come from a cache or CDN while the API is already down.