The NTFS file system allows each file to contain multiple "streams" or sets of data. For example a compiler could use streams to store a program's source code, object code, and other data, or a word processing program could use them to store multiple versions of the same document.
Streams are specified by entering a stream name following the file name, for example:
You cannot use wildcards in stream names except when using filename completion.
You can display stream names with the DIR /: option. The file processing commands COPY, DEL, HEAD, LIST, MOVE, TAIL and TYPE support file streams when the stream name is explicitly specified; see the individual commands for additional details. Other file-related commands, such as ATTRIB and TOUCH work with the file as a whole, and not with any particular stream or portion of the file data.