SharePoint is fundamentally designed for information workers, but it is designed in such a way that it assists a wide spectrum of users and support staff. Key stakeholders are:
The true beauty of SharePoint is the way that conduct of tasks can be devolved to the lowest possible level:
many tasks can be achieved by business users without IT support;
if a business user cannot perform a function, then in many cases a business administrator can assist;
in the unlikely even that a business administrator cannot perform the task, then there is a large world-wide community that has developed thousands of 'add-ins' and web-parts that can be easily installed by an IT administrator;
in the even more unlikely event that a ready-made 'add-in' is not available, then SharePoint provides a highly structured environment for developers.
SharePoint also provides a framework which is designed to simplify IT development and ongoing administration, in the first instance developers should endeavour to:
develop as a web-part in order to preserve all other site functionality without losing the ability for business users to maintain the site;
if the desired functionality cannot be developed as a web-part, then SharePoint provides a range of other (reversible) development options;
the option for business users to reset components to the 'site definition' is invaluable and great caution should be exercised when making changes that alter components at this level;
generally, (perhaps only as a last resort) is it rarely necessary to customise SharePoint in such a way that the full set of default functionality is altered.