This “depends” on a lot of factors. Under Windows, the HTTP stream is decoded by the kernel! Even when this feature is turned off, there’s still a system service for enabling port sharing so that multiple services can listen on the same port (but different binding paths).
The opposite end of the spectrum is “user mode networking” where the kernel is completely bypassed and the server process accepts data directly from the NIC. This is rare but used in high performance systems that need to process hundreds of gigabits.
The opposite end of the spectrum is “user mode networking” where the kernel is completely bypassed and the server process accepts data directly from the NIC. This is rare but used in high performance systems that need to process hundreds of gigabits.