A truecrypt is 'volume' is an basically encrypted file on the disk. TC will mount that file and make it appear as another drive.
When you go to 'create volume' you can use the full size of the jumpdrive, or you can specify a split (8gb drive, 4gb=locked, 4gb=unlocked).
When you go to 'create volume' you can use the full size of the jumpdrive, or you can specify a split (8gb drive, 4gb=locked, 4gb=unlocked).