Streams will examine the files and directories (note that directories can also have alternate data streams) specified and lists the name and sizes of any named streams it encounters within those files.
The syntax 'file:stream', enables to read and write to alternate data streams provided by NTFS file systems.
Example: echo hello > test:stream
The example creats a stream named 'stream' that is associated with the file 'test'. Note that when you look at the size of test it is reported as 0, and the file looks empty when opened in any text editor. To see the stream enter 'more < test:stream' (the type command doesn't accept stream syntax so you have to use more).