Change management overview
As outlined in the section on installing apps from AppExchange Marketplace, you should properly evaluate the functionality and results of deploying an app within your Salesforce CRM organization. This concept is part of a wider concern, which addresses the way changes are applied to the Salesforce CRM application.
With the use of Salesforce sandboxes, you can properly evaluate and perform due diligence for new Salesforce functionality before deciding to roll it out to your users in the production system. In the case of an AppExchange app, if the app proves to be unsuccessful, then it need not be uninstalled.
Salesforce sandboxes
Sandboxes are separate Salesforce CRM environments that are isolated from your Salesforce production organization, so actions that you carry out in your sandboxes do not affect your Salesforce production environment, and vice versa.
To view and manage your existing sandboxes or create new ones in Salesforce CRM, navigate to Setup | Sandboxes...
