What is persistent data?

Persistent data refers to information that is designed to remain intact even after a system has been powered off or rebooted. This type of data is typically stored in non-volatile memory components such as hard drives, SSDs, or other storage media, which allows it to be preserved across sessions. The ability for data to persist is crucial for applications that must retain user settings, application states, databases, and any other critical information that should be accessible at a later time.

When considering the other choices, data that disappears when the system is powered off indicates volatility, such as data stored in RAM, which is lost when the power is turned off. Similarly, easily modifiable data doesn't capture the essence of persistence, as modifiability pertains to how data can be changed rather than its capacity to remain intact across system reboots. Lastly, data temporarily cached in RAM is, by definition, non-persistent, as it is cleared when the system stops running or is rebooted. Thus, option C accurately characterizes persistent data, positioning it as essential for maintaining continuity in computing environments.