Describe what happens network-wise when a browser requests a page — for example, you enter a link in the address bar. Outline all steps from that moment until the HTML code is received.
sobes.tech AI
Answer from AI
When a URL is entered in the browser and Enter is pressed, the following network process occurs:
-
URL Parsing: The browser extracts the protocol (e.g., https), domain name, and path.
-
DNS Query: The browser contacts the DNS server to obtain the IP address of the server by the domain name.
-
Establishing TCP Connection: A TCP connection is established with the server using the obtained IP and port (usually 443 for HTTPS).
-
TLS Handshake (for HTTPS): Certificates and keys are exchanged to establish a secure channel.
-
Sending HTTP Request: The browser forms an HTTP GET request with the required path and headers and sends it to the server.
-
Server Processing: The server receives the request and processes it (e.g., generates HTML or serves a static file).
-
Server Response: The server sends an HTTP response with a status code (e.g., 200 OK) and the body — the HTML code of the page.
-
Receiving and Processing Response: The browser receives the response, begins parsing the HTML, and loads additional resources (CSS, JS, images) via links within the page.
-
Page Rendering: The browser constructs the DOM, CSSOM, executes JS, and displays the page to the user.
Thus, from entering the URL to displaying the page, many network and internal browser operations occur, ensuring the loading and rendering of the web page.