Categorize, describe, and give examples of the major functions of operating systems. According to Operating System Concepts Essentials (2014), operating systems' primary functions include CPU scheduling, memory management, communication management, synchronization, error detection, resource allocation, accounting, and protection and security. Also, the explanation of algorithms, structures, and threads. The functionalities are interface (UI) is what the user sees and interacts with to natural processes on the computer. The UI can be a command line, batch interface, or a graphical user interface (GUI) (Silberschatz, Galvin, Gagne, 2014). Program execution refers to the ability to start and stop a program. A program first needs to be loaded to the main memory to execute and can then be terminated normally or through an error. I/O operations are managed through the operating system so as not to introduce user error when a program calls for input or output from/to