It depends on the Landscape of your environment

Example: Sandbox – Development – Testing or Quality -

Production

In support process usually you replicate the issue that the

user has got in the testing or quality environment and then

try for a solution.

In Implementation, sandbox is used as a rough book to try

implementing and doing experiments, later you do a clean

configuration in Development and then transport the same to

Testing or Quality and finally go live to the production

environment.

Note: The above mentioned is just an example, the landscape

and process can be different from organization to

organization.