Clarify potentially confusing documentation relating to blaze server processes.

--
PiperOrigin-RevId: 142489262
MOS_MIGRATED_REVID=142489262
diff --git a/site/versions/master/docs/bazel-user-manual.html b/site/versions/master/docs/bazel-user-manual.html
index 8cba504..d29ad06 100644
--- a/site/versions/master/docs/bazel-user-manual.html
+++ b/site/versions/master/docs/bazel-user-manual.html
@@ -72,12 +72,14 @@
 </p>
 <p>
   When you run <code>bazel</code>, you're running the client.  The
-  client finds the server based on the path of the base workspace directory
-  and your userid, so if you build in multiple workspaces, you'll have
-  multiple Bazel server processes.  Multiple users on the same
-  workstation can build concurrently in the same workspace.  If the
-  client cannot find a running server instance, it starts a new one.
-  The server process will stop after a period of inactivity (3 hours,
+  client finds the server based on the output base, which by default is
+  determined by the path of the base workspace directory and your
+  userid, so if you build in multiple workspaces, you'll have multiple
+  output bases and thus multiple Bazel server processes.  Multiple
+  users on the same workstation can build concurrently in the same
+  workspace because their output bases will differ (different userids).
+  If the client cannot find a running server instance, it starts a new
+  one. The server process will stop after a period of inactivity (3 hours,
   by default).
 </p>
 <p>