What defines a portable storage device?

A portable storage device is defined as a removable component that stores data or information, which is precisely why the chosen answer aligns with the definition. These devices are designed to easily connect and disconnect from computers or other systems, allowing for data transfer, backup, and portability. Examples of portable storage devices include USB flash drives, external hard drives, and memory cards. Their removable nature facilitates convenience in transporting data between different machines and for personal use, making them a critical tool in both personal and professional settings.

The other options focus on fixed or non-removable components, which do not fit the definition of portable storage. For instance, a permanently connected device or fixed server would not allow for easy transport or removal, and a device that only logs information does not imply the capability to store and transfer data in the same manner. Therefore, the definition of a portable storage device is specifically tied to its capacity to be a removable storage medium.