Question : Difference between permissions on SHARING TAB and SECURITY TAB

Can someone explain the difference in the two?

I'm not very clear.  If I share something out, I have the option to click on the PERMISSIONS button.  Is this the same as going over to the security tab?  Why would I set permissions in one over the other?

Answer : Difference between permissions on SHARING TAB and SECURITY TAB

Here is how I would go:

Security Permissions (on the security tab)
      Refer to the permissions for that specific folder on the local machine itself, not through the network share, you can selectively allow say for example, only administrator to access certain folder on the local machine without sharing that folder, so that when anybody else except the administrator logs on to that machine locally does not get the access to that particular folder.

Sharing Permissions
     Its essentially the same as the security permission but it defines who will have the permissions, when the folder is accessed through the network share.

Security tab settings will override the settings of the sharing tab, for obvious reasons that machine does not permit any user except the admin to access the folder locally so it will not allow that through the network as well.

Hope this helps
--Dee