What change management tools are available for deploying Salesforce customisations?

Change Sets: GUI-based metadata migration between orgs connected via Deployment Connection. Outbound change sets are created in the source org; inbound sets are validated and deployed in the target org. Limitations: one-directional, cannot delete metadata, not all metadata types supported, no version control.
Salesforce CLI (sf): Command-line tool supporting source-driven development. Commands: sf project deploy start and sf project retrieve start for deployment and retrieval. Supports all metadata types and can be integrated into CI/CD pipelines.
Sandbox types for testing: Developer (5 MB storage), Developer Pro (1 GB), Partial Copy (5 GB with sample data template), Full Copy (production data replica). Refreshed from production on demand.
Sandbox refresh and data templates: A data template (configured in Setup) specifies which standard/custom objects and their relationships are included when refreshing a Partial Copy sandbox.
Third-party tools: Gearset, Copado, AutoRABIT, and Flosum provide version control integration, automated testing, and deployment pipeline management beyond native Salesforce tools.