The main function of a ‘sandbox’ in software testing is to create a secure environment for developers to test applications without affecting the live system. This isolated space allows for experimentation, validation, and troubleshooting of new features or updates safely. Sandboxes prevent unintended disruptions to ongoing operations and mitigate security risks by containing any issues arising from the test. Ultimately, they enable teams to refine software quality and performance before full deployment in the production environment.