As mentioned above, Info format is mostly a plain text transliteration of the Texinfo source, with the addition of a few control characters to separate nodes and provide navigational information, so that Info-reading programs can operate on it.
Info files are nearly always created by processing a Texinfo source
document. texi2any, also known as makeinfo, is
the principal command that converts a Texinfo file into an Info file;
see texi2any: The Translator for Texinfo.
Generally, you enter an Info file through a node that by convention is named ‘Top’. This node normally contains just a brief summary of the file’s purpose, and a large menu through which the rest of the file is reached. From this node, you can either traverse the file systematically by going from node to node, or you can go to a specific node listed in the main menu, or you can search the index menus and then go directly to the node that has the information you want. Alternatively, with the standalone Info program, you can specify specific menu items on the command line (see Info).
If you want to read through an Info file in sequence, as if it were a printed manual, you can hit SPC repeatedly, or you get the whole file with the advanced Info command g *. (See Advanced Info commands in Info.)
The dir file in the info directory serves as the departure point for the whole Info system. From it, you can reach the ‘Top’ nodes of each of the documents in a complete Info system.
If you wish to refer to an Info file via a URI, you can use the (unofficial) syntax exemplified by the following. This works with Emacs/W3, for example:
info:emacs#Dissociated%20Press info:///usr/info/emacs#Dissociated%20Press info://localhost/usr/info/emacs#Dissociated%20Press
The info program itself does not follow URIs of any kind.