whitelist - what is it?

[Johnwf]

hi,
can someone please tell me what the whitelist is used for? I purchased the professional version of spybot yesterday and clicked on the "create whitelist" button. the program has been running over 24 hours now and it says "Processed 510000(+) files of 423769 so far..."
When does it stop? I don't think there are actually a half million files on my pc.
thanks
John F

[Zenobia]

There's an explanation of what the Whitelist is at the top of this page:

When you first install Spybot +AV you will have the option to create a whitelist. This is a list of programs that are known to be safe. This will speed up the scanning process as these files will not be scanned in the future unless they have been altered in some way.
http://www.safer-networking.org/faq/how-to-refresh-the-system-whitelist/