-**Upgrade Manager**:Mainly responsible for upgrading process control. Physical
-nodes information of each node is saved in upgrade manager.
-**VIM Interface**:Mainly responsible for the external interface, include
+- **Upgrade Manager**:Mainly responsible for control of the upgrade process.
+The Escalator is required to know the software deployment information of the
+platform and will use these information during the upgrading. It will be
+collected from some place, such as the Installer, Deploy Manager and Escalator
+itself, etc.
+- **VIM Interface**:Mainly responsible for the external interface, include