To protect intellectual property / Make it illegal to copy or distribute work without permission.
Making a copy of a commercial software disk to sell to a friend.
Work is automatically copyrighted upon creation (1). Illegal for others to use/scan/distribute without permission (1).
Copyright: Automatic legal right to prevent copying (1).
Licence: Agreement/contract granting permission to use the work (1).
Legal: Both protected by CDPA. Creator chooses distribution.
Proprietary: Can charge money, code hidden (protects IP). Limits user base.
Open Source: Collaborative, free distribution. Harder to monetise, code can be copied/seen.
Level 3 (6-8): Detailed comparison. Balanced reasoning.