1. There are three main types of organizational structures: line, functional, and line and staff.
2. The line structure has a vertical hierarchy with authority flowing from top to bottom. It allows for quick decisions but lacks specialization.
3. The functional structure groups employees by specialized skills and expertise. This allows for maximum specialization but can weaken responsibility and decision making.
4. The line and staff structure combines elements of both, aiming to gain the advantages of specialization while maintaining authority and responsibility through vertical lines. It is considered the most advanced type.