Networking

HTTP, HTTPS & TLS

Understand the request/response cycle, status codes, and how TLS secures it.

40 min read intermediate 3 objectives

Status

Not started

What you will learn

  • Read HTTP methods and status codes
  • Explain the TLS handshake
  • Inspect headers

New to this? Start here

The basics, in plain English

When you open a website, your browser sends a request and the server sends back a response. The rules for that conversation are called HTTP. HTTPS is the same thing but encrypted so nobody can read it in transit.

Request
The message your browser sends asking for a page or some data.
Response
The message the server sends back, usually the page plus a status code.
Method (GET/POST)
The verb of a request: GET fetches data, POST sends data to create something.
Status code
A 3-digit result: 200 means OK, 404 means not found, 500 means the server broke.
HTTPS
HTTP wrapped in encryption, so the data is scrambled to anyone listening in between.
TLS
The technology that does the encrypting and proves the site is really who it claims to be.
01

HTTP

Stateless request/response over TCP. Methods (GET, POST...) and status codes (2xx, 4xx, 5xx) carry meaning you must know cold.

02

TLS

TLS wraps HTTP in encryption via a handshake that negotiates keys and verifies certificates. This is HTTPS.

Try it yourself

bash
$curl -v https://example.com
Make a request and print the full request/response, including TLS details.
$openssl s_client -connect example.com:443
Open a raw TLS connection to inspect the certificate and handshake.
$curl -w "%{http_code}" -o /dev/null -s url
Print only the HTTP status code, discarding the body.
↳ lines explain what each command does — only the commands get copied

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