What does "hot swap" capability refer to in workstation hardware?

"Hot swap" capability refers specifically to the ability to replace or add components in a computer system while it is powered on and running. This feature is particularly important for maintaining system uptime and ensuring uninterrupted operation, especially in environments that require high availability, such as servers or critical workstations.

When components such as hard drives or power supplies are designed with hot swap capability, technicians can safely remove a failed or outdated part and replace it without needing to power down the entire system. This leads to reduced downtime and increased efficiency, as users can continue their tasks without interruption.

The other options, while they address different aspects of computing, do not define hot swap capabilities accurately. For example, upgrading software without restarting does not involve hardware, switching between software applications is simply about multitasking, and changing hardware settings through the BIOS does not allow for immediate component replacement. Therefore, the correct answer highlights the essential functionality that hot swapping provides in workstation hardware.