The purpose of a sandbox in software development is to create a controlled environment where developers can test new code or applications without affecting the overall system. Sandboxes allow for safe experimentation, enabling the identification of bugs and performance issues in isolation. This practice helps ensure that code behaves as expected before it is integrated into the main codebase. Additionally, sandboxes can help mitigate security risks by isolating potentially harmful code from critical systems, supporting a more secure development process and reducing the likelihood of system failures.