The webmaster obviously need to have control over all aspects of the site, and must be able to create and update new Categories, Menu entries, install new software etc, and must be able to create Articles and Modules that use PHP code.

In contrast, other members of the Committee may need to be given access to the back-end of the site, but many of the functions should be hidden from them.  This is necessary mainly to keep it simple and avoid confusion, but also because they may inadvertently make changes that could break the site.

Joomla controls this by having different ”User Groups" that are granted different levels of privileged access to the system. The webmaster will be assigned to the group called “Super Users” and will be able to make changes to every single aspect of the system.  If a particular User is in a different User Group, for example in “Manager” then they will be able to create new Articles and amend existing ones but will not have access to other functionality unless it is specifically granted to them.