DROID stands for Digital Record Object IDentification. It's a free software tool developed by The National Archives that will help you to automatically profile a wide range of file formats. For example, it will tell you what versions you have, their age and size, and when they were last changed. It can also provide you with data to help you find duplicates.
This video gives a brief demonstration on how to use DROID, including how to create profiles, add files, understand and filter your results and generate reports.
You can download DROID and find more information and guidance on how to use it and interpret the results at nationalarchives.gov.uk/droid