Compare unlocked packages, managed packages, and change sets for deployment.

Change Sets: Simple UI-based deployment between connected orgs. No version control integration. Cannot delete metadata. Limited metadata type support. Best for small teams with simple deployment needs. Not suitable for CI/CD.

Unlocked Packages (Salesforce DX): Modular, versioned metadata containers. Deployed via Salesforce CLI. No namespace required (or can use one). Owned and modified by the subscriber org — source can be modified after installation. Version control integrated via SFDX project. Supports scratch orgs for isolated development. Best for enterprise teams needing modular, CI/CD-driven deployments.

Managed Packages: ISV/AppExchange packages with a namespace. Source code is locked — subscribers cannot modify the package's Apex code. Supports LMA (License Management App) for ISV licensing. Upgradeable via version releases. Deprecation of fields/objects is complex. Best for commercial products sold on AppExchange.

Architectural decision: For enterprise internal development: use Unlocked Packages for modular DX-based CI/CD. For AppExchange products: use Managed Packages. Change sets are acceptable only for small teams without CI/CD requirements.