An ENC file is a generic encoded file that may use one of several different types of proprietary or standard encodings. It is encoded to help protect the file from unauthorized use, or to help set up the file for a particular use, such as Internet transfer.

ENC files may be encoded in the .UUE format, which can be opened with a program such as StuffIt Deluxe. However, ENC files that use a proprietary encoding can only be opened by the program that encoded the file.