In Italy an assessor (in Italian language: assessore) is a member of a Giunta, the executive body in all levels of local government: regions, provinces and communes.
Assessors are appointed by the chief executive of local government, who chairs the Giunta--the mayor of a commune, the president of a province or region. They serve until the chief executive ends his term or resigns, if he doesn't dismiss them.
In communes with 15,000 residents or more and in provinces, assessors cannot be members of Consiglio (council), the local legislative body: if a member of council is appointed as assessor, he must resign from council.
The mayor or president usually assigns to each assessor responsibility for a specific aspect of municipal, provincial or regional affairs and the supervision of corresponding branch of local government, called assessorato (department). Among the assessors one is chosen by mayor or president as his deputy and is called vicesindaco (deputy mayor) or vicepresidente (vice president).