The primary distinction between public and private clouds lies in their accessibility and ownership. Public clouds are services offered over the internet to multiple users and organizations, managed by third-party providers like Amazon Web Services (AWS) and Microsoft Azure. In contrast, private clouds are dedicated infrastructures for a single organization, providing greater control, security, and customization. Organizations may choose private clouds for sensitive data handling, while public clouds are preferred for their scalability and cost-effectiveness, allowing users to access services without investing in physical hardware.