Hi

I've tried finding the terminology and knowhow on how to do the following for such a long time so would really appreciated any advice:

Left hand menu to reflect the pages assoicated to its parent e.g. Business section on site and when you go to that section the pages under business are shown on left, like www.southwark.gov.uk

Please tell me what Drupal calls this and how it is easily done.

Many thanks

Steve