Which component ensures the execution of multiple applications simultaneously on a computer system?

The component that ensures the execution of multiple applications simultaneously on a computer system is system software. This type of software includes operating systems that manage the hardware and software resources of the computer. The operating system allows for multitasking, which makes it possible for several applications to run at the same time by efficiently allocating CPU time and memory to each application. It handles the scheduling, execution, and management of processes, ensuring that they can operate concurrently without interfering with one another, thus providing a seamless user experience.

In contrast, a database system primarily deals with data management and may run on top of the system software but does not directly control the execution of multiple applications. The end user is simply the person interacting with the computer and applications, and networking hardware pertains to the physical components that enable networking capabilities, which is unrelated to the core function of executing applications simultaneously on the computer.