+<h2>Sessions</h2>
+<p>
+ An <dfn>Ardour session</dfn> is a container for an entire project. A
+ session may contain an arbitrary number of <dfn>tracks</dfn> and
+ <dfn>busses</dfn> consisting of audio and MIDI data, along with
+ information on processing those tracks, a mix of levels, and everything
+ else related to the project. A session might typically contain a song, or
+ perhaps an entire album or a complete live recording.
+</p>
+<p>
+ Ardour sessions are held in directories; these directories contain one or
+ more <dfn>session files</dfn>, some or all of the audio and MIDI data and
+ a number of other state files that Ardour requires. The session file
+ describes the structure of the session, and holds automation data and
+ other details.
+</p>
+<p>
+ Ardour's session file is kept in XML format, which is advantageous as it
+ is somewhat human-readable, and human-editable in a crisis. Sound files
+ are stored in one of a number of optional formats, and MIDI files as SMF
+ (standard MIDI format).
+</p>
+<p>
+ It is also possible for Ardour sessions to reference sound and MIDI files
+ outside the session directory, to conserve disk space and avoid
+ unnecessary copying if the data is available elsewhere on the disk.
+</p>
+<p>
+ Ardour has a single current session at all times; if Ardour is started
+ without specifying one, it will offer to load or create one.
+</p>
+<p>
+ More details can be found at
+ <a href="/working-with-sessions">Working With Sessions</a>.
+</p>