What type of files may contain information that can aid in investigations but were not directly part of the active data?

Hibernation files are an essential type of file in the context of digital investigations because they contain a snapshot of the system's memory at the moment the computer was put into hibernation. This allows investigators to recover information about all running processes, open applications, and active user sessions at that point in time. Because the hibernation file captures the complete state of the system's memory, it holds valuable data that may not be available in the active data forms.

Cache files, temporary files, and system files all play various roles in a computer's operations, but they don't encapsulate the entire memory state as hibernation files do. Cache files are often designed for efficiency in data retrieval and might not retain critical information about ongoing tasks. Temporary files may contain fragments of data that were in use but typically do not provide a comprehensive overview of system activity. System files are integral for the operation of the system but do not explicitly save user or operational states at the time of hibernation. Thus, hibernation files are particularly valuable for forensic analysis and investigations, making them the most relevant choice in this context.