This is the official manual for the latest Org-mode release.
:tangle header argument specifies whether or not the code
block should be included in tangled extraction of source code files.
tangleThe code block is exported to a source code file named after the full path (including the directory) and file name (w/o extension) of the Org mode file. E.g.,
noThe default. The code block is not exported to a source code file. E.g.,
:tangleheader argument is interpreted as a path (directory and file name relative to the directory of the Org mode file) to which the block will be exported. E.g.,