Fundamentals
The building blocks of engineering —protocols, encryption, networks— explained with precision and the judgment of someone who runs mission-critical platforms. No empty jargon, no shortcuts that mislead. What everyone should understand.
Both move files. Only one encrypts what travels —credentials included. The difference that isn't optional in banking, and why SFTP is not "secure FTP".
What an HTTP request really is, what TLS adds, and what the browser padlock does —and does not— tell you.
Two families of keys with opposite strengths. Why TLS doesn't pick one, but combines both.
What a certificate is, who signs it, and how the chain of trust that holds up the web is built.
The most common confusion of all. What a hash is, how it differs from encryption, and why it matters for your passwords.
The choreography of systems that runs in under a second: from name to IP, the connection, the request and the render.
How a name becomes an IP, why a change "takes time to propagate", and what you see —and don't— when DNS fails.
Public and private addresses, why your whole network goes out with a single IP, and how it's segmented to isolate what's critical.
Guaranteed delivery or speed with no promises. Why a payment demands TCP and a video call prefers UDP.