cache.match subrequests

Hey, does the Cloudflare's Worker Cache API function cache.match run a subrequest to the request object when the cache misses?
In the docs, I can see that https://developers.cloudflare.com/workers/runtime-apis/cache/#parameters-1 if there's a header called

cache.match()

cache.match()

? then a subrequest is never sent to the origin? Kinda getting lost here, how is that a valid header name?

Thanks for the help!

Cloudflare Docs

Control reading and writing from the Cloudflare global network cache.