MTP Server
MTP is a driverless way to transfer files from your Nintendo Switch to your PC. It can transfer any file under 4GB. You simply connect your USB cable from your Switch to your PC and start Tinfoil.
Installed
Lists all of your currently installed applications as a virtual NSP file. CVopying any of these files to your PC allows you to dump any installed application (under 4GB) to your PC.
Copying a NSP or NSZ file to this directory immediately installs that file.
Firmware
Lists a single NSP file that represents your currently installed firmware. Copying this file allows you to backup your firmware.
Copying a firmware NSP file to this directory immediately installs that firmware.
Index
Lists all remote NSP files indexed by Tinfoil.
This allows you to copy remote files to your PC. This however is limited by strict timeout values, therefore it will only work if your remote file has fast response times.
System
Files on your Nintendo Switch's system partition.
User
Files on your Nintendo Switch's user partition.
sdcard
Files on your Nintendo Switch's microSD card.