What is the correct term for activating updates in a development environment before full deployment?

The term that accurately describes the process of activating updates in a development environment before full deployment is staging. Staging refers to the practice of creating an environment that closely replicates the production environment where changes can be tested thoroughly before they are pushed to the live environment. This allows for the identification of any issues or bugs, ensuring that the updates will function correctly when they go live.

Testing typically refers to verifying that the software meets specific requirements, but it does not specifically encompass the broader process of preparing for deployment as effectively as staging does. Reviewing focuses more on the assessment or evaluation of updates rather than the deployment process itself. Sandboxing, while it can involve creating isolated environments for testing, is more about experimentation and less about preparing updates for deployment. Thus, staging clearly aligns with the correct context of the question regarding preparing updates for a full rollout.