Question : whats the difference between sharing and security?

Im looking to set up folders for students to save their work to.  The folders are stored on a server I just set up.  I set all the folders with sharing permissions.  I shared individual folders with the students the folder belongs to and the 2 teachers that teach the class.   I Did not add anyone to the security tab.  The students nor the teachers are able to open the folders unless I add their names to the security tab.  Was I suposed to add them to the security tab and not the sharing tab?   Im not sure what the difference is.

Answer : whats the difference between sharing and security?

Share permissions are nearly pointless.  A share is like a doorway to the disk.  Shares only allow you to control permissions on that one doorway.

NTFS is the file system used in Windows.  It allows permissions to apply to each and every file and folder.

When evaluating permissions, Windows uses the MOST RESTRICTIVE permissions.  Meaning, if the share says EVERYONE: Full Control but the NTFS Security says EVERYONE: Read Only, then everyone has read only and vice versa.

Because NTFS permissions can be granularly applied to files and folders and share permissions ONLY apply to the share, I usually IGNORE share permissions, setting them to EVERYONE FULL and then assigning NTFS permissions (Security Tab).