fileencoding: character encoding Vim to edit a file present, will save the file when Vim save files as this character encoding (whether new documents are true).
fileencodings: it will follow the character encoding listed one by one to detect the character encoding of the file will open Vim starts, and fileencoding set as the final detected character encoding.
encoding: character encoding used inside Vim, Vim comprising a buffer (buffer), menu text, text messages and the like.
termencoding: If Vim terminal environment, and the need to set the encoding used by the terminal termencoding coincide.
