SFDX (Salesforce Developer eXperience) is a new set of tools and features that help shift development from an org-based model to a source-based development model. Key concepts include scratch orgs, source tracking with version control systems like Git, and unlocked packages. The SFDX CLI (command line interface) is used to create and manage scratch orgs, push and pull source between orgs and local repositories, and more. Scratch orgs are temporary orgs used for development and testing. Continuous integration and delivery can be achieved by deploying source or packages between orgs. SFDX works with both new and existing Salesforce projects and supports common development tasks like running tests and deploying metadata
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