All GNU software provides its documentation in the info format. This is normally a different format from the man page, and uses a ``menu'' feature to allow pages of related material to be ``linked'' together, allowing cross-references to be placed with a page to provide broader discussion of the various topics. The info command will also display the man page if there is no index to the keyword you supply. For instance:
info lpc
will simply display the man page for the lpc program in much the same way that man did earlier. On the other hand, if the command had been:
info diff
The format of the info page for diff will be printed to the screen. q will exit info, and the man command with diff as the argument, will display the man page for diff, which you will see is quite different. Some folks like the terse structure found in man pages, while others like the expansive discussion provided by the info pages. Debian provides for both types of individual by providing both whenever possible.