What component captures live events and saves them as video files in an auxiliary device?

The component responsible for capturing live events and saving them as video files in an auxiliary device is a recorder. A recorder is designed specifically for this function, often equipped with features that allow it to take input from various sources, such as cameras or audio equipment, and store the resulting media in a digital format. This capability is essential for tasks like surveillance, broadcasting, and personal video recording, where the playback of real-time events is necessary.

In comparison, a camera's primary role is to capture images and videos but does not have the ability to save these files independently; it needs to be connected to a recording device to store the content. A power splitter is used to distribute a signal from one source to multiple devices but does not handle video capture or storage, and a monitor serves as a display device for viewing content but does not perform any recording function. Thus, the recorder distinctly fulfills the requirement of saving live events as video files, making it the correct choice in this context.