Final answer:
A timeline through a body file involves collecting system files, application files, and user files. These files help create a detailed sequence of events for investigative purposes in digital forensics.
Step-by-step explanation:
When creating a timeline through a body file, the three types of files that are typically collected include: system files, application files, and user files. System files are critical for the operation of the operating system and may include logs, system databases, and configuration files. Application files are those related to software programs installed on the system, such as program executables, logs, and configuration files. Lastly, user files are those that are created, modified, or accessed by the user, including documents, spreadsheets, and multimedia files.
Note that in digital forensics, these file types are critical for establishing a clear and accurate sequence of events in investigative timelines. The proper collection and analysis of these files can provide insights into system activity, application usage, and user behavior which might be pivotal in forensics or cybercrime investigations.