The end-to-end map that connects everything else on this blog — and doubles as the answer to a very common interview opener.
The journey of annauniversityplus.com
- DNS: browser cache → OS → resolver → "which IP owns this name?" (~20–120ms, then cached)
- TCP handshake with that IP, then TLS — certificates verified, encryption keys agreed (the 🔒)
- HTTP request:
GET / HTTP/2+ headers (cookies, accepted formats) - Server work: static file read OR code runs (this site: PHP includes header, renders content) → HTML response
- Browser pipeline: parse → fetch CSS/JS/images (each repeating steps 1–4, mostly cached) → render pipeline → pixels
Where a CDN fits
A Content Delivery Network keeps copies of static files in 100+ cities. A Chennai student hits the Chennai edge (~10ms) instead of a Frankfurt origin (~150ms). DNS points at the CDN; the CDN fetches from your origin once, then serves everyone nearby. Cloudflare's free tier does this for any site.
Why this model matters daily
- Slow site? You now know the five places latency hides
- "Static vs dynamic hosting" (the hosting guide) is just "does step 4 run code?"
- Every security topic (HTTPS, cookies, CORS) lives at a specific step