What exactly do HTTP headers do, and why should you care? or Can someone explain what HTTP headers do

http headers do the boring-but-necessary paperwork. Like, your browser sends `Accept-Encoding: gzip` to say "yo, send compressed data," and the server replies with `Content-Encoding: gzip` to confirm.

They’re *everywhere*:
- Session management (`Set-Cookie`)
- CORS (cross-origin rules)
- Even tracking (ugh, `Referer` header)

For learning, I’d recommend the "HTTP Headers" section on SSLLabs—it’s technical but worth it.