Complex sentence: Once exhibits have been seized an exact sector level duplicate (or "forensic duplicate") of the media is created, usually via a write blocking device, a process referred to as "Imaging" or "Acquisition".
Split into simpler sentences: Once exhibits have been seized, an exact sector level duplicate (or "forensic duplicate") of the media is created, usually via a write blocking device. The duplication process is referred to as "Imaging" or "Acquisition".