A full copy sandbox is a copy of a production environment that includes all data and metadata. It is suitable for user testing because it provides a realistic and isolated environment where users can test changes without affecting live data or users. Power users are users who have extensive knowledge and experience with the business domain and processes. They can provide valuable feedback and insights on whether the solution meets their expectations and requirements. A scratch org is a temporary and lightweight environment that is suitable for development and testing of code-based changes, but not for user testing of declarative changes. A partial sandbox is a copy of a production environment that includes some data and all metadata. It is suitable for quality assurance testing, but not for user testing because it may not have enough data to cover all scenarios. References: 1
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