+ <refsect1>
+ <title>Special Slice Units</title>
+
+ <para>There are four <literal>.slice</literal> units
+ which form the basis of the hierarchy for assignment
+ of resources for services, users, and virtual machines
+ or containers.</para>
+
+ <variablelist>
+ <varlistentry>
+ <term><filename>-.slice</filename></term>
+ <listitem>
+ <para>The root slice is the
+ root of the hierarchy. It does
+ not contain services directly,
+ but is used to set defaults
+ for the whole tree.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><filename>system.slice</filename></term>
+ <listitem>
+ <para>This slice contains
+ services started by
+ <command>systemd</command>.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><filename>user.slice</filename></term>
+ <listitem>
+ <para>This slice contains user
+ processes and services started
+ on behalf of the user,
+ including the per-user systemd
+ instance.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><filename>machine.slice</filename></term>
+ <listitem>
+ <para>This slice contains
+ virtual machines and
+ containers registered with
+ <command>systemd-machined</command>.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+