Texinfo(1) is a documentation system that uses a single source file to produce both on-line information and printed output. This means that instead of writing two different documents, one for the on-line help or other on-line information and the other for a typeset manual or other printed work, you need write only one document. When the work is revised, you need revise only one document. (You can read the on-line information, known as an Info file, with an Info documentation-reading program.)