This document discusses Heroku Connect, a service that provides bi-directional data sync between Salesforce and Heroku Postgres. It allows developers to more easily build customer-facing apps by leveraging familiar tools like Postgres and standard workflows while keeping data secure in Salesforce. Heroku Connect works by synchronizing data for standard or custom objects using timestamps to detect changes and implementing a "last writer wins" approach. It automatically maps objects and tables during setup. Best practices include updating mappings for deleted fields and being careful of validation rules or required fields on insert.