HTTP and HTTPS
HTTP & HTTPS: Overview
What Are HTTP and HTTPS?
HTTP (Hypertext Transfer Protocol) and HTTPS (Hypertext Transfer Protocol Secure) are the two primary protocols used for communication between web browsers and web servers.
| Protocol | Port | Purpose | When It’s Used | Where It’s Used |
| HTTP | 80 | Transfers web pages and resources | Used for non-secure websites and testing | Blogs, informational sites, local development |
| HTTPS | 443 | Secure version of HTTP with encryption | Used for secure browsing and transactions | Banking sites, e-commerce, login pages, API communication |
How HTTP and HTTPS Work
- HTTP
- A client (browser) sends a request to a web server.
- The server processes the request and sends back a response (e.g., a webpage).
- Data is transferred in plaintext, meaning it can be intercepted by attackers.
- HTTPS
- Functions like HTTP but encrypts data using TLS (Transport Layer Security) or SSL (Secure Sockets Layer).
- Prevents eavesdropping and data manipulation by encrypting the communication.
- Requires an SSL/TLS certificate issued by a trusted Certificate Authority (CA).
Why HTTPS Is Important
| Feature | HTTP | HTTPS |
| Encryption | ❌ No encryption | ✅ Encrypted using TLS |
| Data Security | ❌ Vulnerable to attacks | ✅ Protected from eavesdropping |
| Authentication | ❌ No verification | ✅ Ensures site legitimacy |
| SEO Ranking | ❌ No advantage | ✅ Preferred by search engines |
| Trust Indicator | ❌ “Not Secure” warning in browsers | ✅ Shows a padlock icon |
Analogy: HTTP vs. HTTPS
- HTTP is like sending a postcard—anyone can read the message.
- HTTPS is like sending a sealed envelope—only the recipient can read it.
Understanding HTTP Methods
HTTP methods define the type of request a client sends to a server.
| Method | Purpose | Example |
| GET | Requests data from the server | A user loads a webpage (GET /index.html) |
| POST | Submits data to the server | Logging in (POST /login) |
| PUT | Replaces a resource on the server | Updating a user profile (PUT /user/123) |
| PATCH | Partially updates a resource | Changing only the email (PATCH /user/123) |
| DELETE | Removes a resource | Deleting an account (DELETE /user/123) |
Use Case Examples
- GET: Visiting https://example.com/products to see all products.
- POST: Submitting a contact form.
- PATCH: Changing only a user’s email address without modifying other data.
- DELETE: Removing a product from an e-commerce store.
Popular HTTP Status Codes
HTTP status codes indicate the result of a request.
| Code | Meaning | Example Scenario |
| 200 OK | Request successful | A webpage loads correctly |
| 201 Created | Resource successfully created | A user registers on a site |
| 301 Moved Permanently | URL has changed | Old domain redirects to a new one |
| 302 Found (Temporary Redirect) | Temporary URL change | A login page redirects to a dashboard |
| 400 Bad Request | Invalid client request | A form submission is missing required fields |
| 401 Unauthorized | Authentication needed | Accessing a private API without logging in |
| 403 Forbidden | Access denied | A user without admin privileges tries to open an admin page |
| 404 Not Found | Resource does not exist | A broken link leads to a missing page |
| 500 Internal Server Error | Server-side issue | A website crashes due to a coding error |
| 503 Service Unavailable | Server temporarily down | A site is overloaded with traffic |
Final Thoughts
- Always use HTTPS for secure transactions, logins, and sensitive data transfers.
- Understanding HTTP methods helps in web development and debugging.
- HTTP status codes provide insights into server responses and troubleshooting.