Explanation

• Each model defines a specific entity associated with the CRM system, outlining the necessary fields and relationships.
• Relationships between models are established using foreign keys and defined using relation directives in Prisma.
• Inline comments provide context for each field and model, aiding in understanding the data structure.
• This schema follows normalization practices and provides a robust foundation for a scalable CRM backend in Node.js using Express and PostgreSQL.

Feel free to ask if you have any questions or need further clarifications!