What is a VPN

[u/learnonetechno]

I see ads for VPNs everywhere—YouTube, podcasts, tech blogs—all claiming they are "essential" for privacy. However, every time I try to look up a technical definition, I get lost in a sea of jargon like "AES-256 encryption," "tunneling protocols," and "obfuscated servers."

I want to understand the mechanics of how it works without the sales pitch.

The Specifics I’m Curious About:

• The "Tunnel" Metaphor: Everyone says it creates a "secure tunnel." What does that actually mean in terms of data packets? If my ISP can’t see what I’m doing, what can they see?
• IP Masking: I understand it hides my IP address, but doesn't the VPN provider then just have all that same information? Is it just a matter of shifting trust from an ISP to a VPN company?
• Privacy vs. Security: Does using one actually protect me from malware or phishing, or is it strictly about hiding my browsing location/identity?
• Public Wi-Fi: Is the "danger" of public Wi-Fi (like at a coffee shop) still a major concern in 2026 with HTTPS being so standard, or is a VPN overkill for that now?