Explanation:

- Embedded: These operating systems are designed for specific devices and often have limited functions. They are optimized for the hardware they run on.

- Real time: These are designed to process data and respond to inputs or events within a guaranteed timeframe. They are used where timing is critical, such as in automotive systems, medical devices, or industrial control systems.

- Multiuser: These allow multiple users to access and use the system resources concurrently. They focus on managing resource allocation among users.

- Synchronized: This is not a standard category for operating systems and may refer to operations that occur at the same time.