when I was working on a project recently, I involved the preflight pre-checking mechanism. A doubt arises:
Why does the browser have to pre-check with the server to confirm that the request is available? Instead of sending the request directly to the server? Whether the request will create
to the serveraffects this category that is no longer on the browser side, so why does the browser stipulate that a pre-request should be sent first? What is the meaning of doing so
? Are there any seniors who know the relevant knowledge? Can you share some relevant examples? Thank you all first.