Users will often have different areas of responsibilities and therefore can be assigned different roles that will allow your users to update different areas of your undesign site (if desired, of course).  This control is entirely up to you. To see this in action, use the following logins:

To update the Home page, log in as:
User: home
Pass: undesign

To update the Announcements page, log in as:
User: announce
Pass: undesign

To update the Events page, log in as:
User: events
Pass: undesign

To update ALL PAGES log in as:
User: superuser
Pass: undesign

This Undesign Demo site is refreshed periodically, and has a few Undesign features enabled for you to try out how easy it is to edit a web site with Undesign.