RAID level 0, also known as striping, involves splitting data evenly across two or more disks without parity information, redundancy, or fault tolerance. This means that if one drive fails, the entire array fails, resulting in total data loss. RAID 0 is typically used to increase performance, as it allows for faster read and write operations by using multiple disks simultaneously. However, because it does not duplicate data across the disks, it does not provide any form of data redundancy.

Daniel is adopting a Reactive network security approach. This approach involves monitoring network traffic to detect any abnormalities or intrusions as they occur. The goal of reactive security is to identify and respond to threats in real-time. It is a part of the broader defense strategy that includes Protect, Detect, Respond, and Predict, where `Detect' aligns with the reactive approach. By using network monitoring tools, Daniel is able to observe the network for any signs of compromise or unusual activity and then take appropriate action to mitigate the threat.

The Encrypting File System (EFS) is a feature of the NTFS file system that provides encryption at the file system level. It is designed to work specifically with NTFS and does not support the FAT file system. When files encrypted with EFS are copied or backed up to a volume that uses the FAT file system, the encryption is lost because FAT does not support EFS encryption. This is why David found that the backup files were not encrypted after transferring them to a system that supports the FAT file system.