#networking

The S in HTTPS is TLS, and it buys three things people lump into "encryption": confidentiality, integrity, and authentication. The one nobody mentions, authentication, is the one that actually matters.

A CDN puts copies of your content on servers near your users so the bytes travel a short distance instead of crossing an ocean every request. The thing most people miss: the bottleneck usually isn't bandwidth, it's latency, and latency is bounded by the speed of light.

Most home internet plans give you 10x more download than upload, and most users never wonder why. The answer is partly engineering and partly an industry decision that's harder to undo than to maintain.

An Ethernet cable carries data between computers and a network at speeds that have grown 100,000x since 1980 without anyone really noticing. Here's what's actually inside one and why categories matter.