What is "launch efi shell from filesystem device" from the boot manager?

Im trying to boot my laptop from my USB Flash drive with its USB Legacy disabled and the internal Hard Drive has no Operating system (clean). After i entered the "launch efi shell from filesystem device" from the boot manager it brought me to a loading screen with windows 10 logo and below is "Automatic repairing" and "Diagnosing your PC". So what does it do? Will it boot my USB Flash drive that has windows 10 installer successfully?

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