When you work in Admin mode, you are connected to your consolidated or remote database and working live. In Model mode, by contrast, you are in a disconnected state, making changes to an XML file that you later deploy.
Admin mode allows you to use a graphical interface to perform the tasks that might otherwise be done in Model mode, programmatically, or with system procedures or SQL statements. Sybase Central provides property sheets that let you configure object properties and wizards that walk you through the steps for performing common administrative tasks.
When you make changes outside of Model mode, you cannot reverse-engineer them into the model.