manual/include/preferences-and-session-properties.html

<p>
  Ardour splits its configuration options into two categories:
</p>
<ul>
  <li>
    Global <dfn>preferences</dfn> control general workflow and system 
    configuration, and should apply to all sessions. They are located in
    <kbd class="menu">Edit &gt; Preferences</kbd> and stored in 
    Ardour's <dfn>user configuration file</dfn> in your home directory. 
  </li>
  <li><dfn>Session properties</dfn> control aspects of the workflow or
    configuration that pertain to the current session only. You can find them
    in <kbd class="menu">Session &gt; Properties</kbd>, and they will be stored
    in the session file.
  </li>
</ul>