A Prospector export will have multiple columns available for you to filter or obtain further information on the companies/people - if you're ever unsure of what these columns mean just click on the Help button found on Step 3 of Prospector:
You'll be prompted to select which kind of information you are querying:
- Company Information
- People Information (only applicable if you have chosen to include People Data)
- Legal Status
Just click on the area you are interested in and you'll see a table providing definitions for every column in the export. For most queries you'll want the Company Information details.
NB: These definitions will also apply to Company Data exports.