What is the difference between HTTP and HTTPS?

Core Difference

HTTP (HyperText Transfer Protocol) transmits data in plain text without encryption. HTTPS (HTTP Secure) adds a TLS/SSL encryption layer on top of HTTP to ensure secure data transmission.

Key Differences

Feature	HTTP	HTTPS
Default Port	80	443
Encryption	None	TLS/SSL encrypted
Security	Low, vulnerable to eavesdropping and MITM attacks	High, encrypted transmission
Certificate	Not required	SSL certificate required
SEO	Lower ranking	Preferred by Google

How HTTPS Works

1. Client initiates a connection request
2. Server returns an SSL certificate (containing public key)
3. Client verifies the certificate's validity
4. Both sides exchange a symmetric key via asymmetric encryption
5. Subsequent communication is encrypted with the symmetric key

Why Use HTTPS?

• Prevent eavesdropping: Data is encrypted, third parties cannot read the content
• Prevent tampering: Data integrity checks prevent man-in-the-middle modifications
• Authentication: Verifies the server's true identity
• SEO advantage: Search engines rank HTTPS sites higher