force.com platform have three diff type of sanbox account which is use to develop and test and maintain the force.com platform applications.
Here am trying to mention i.e salesforce.com is a company name force.com is the salesforce.com company developed development platform.
Sandbox:
1.Developer sanbox
2.Configuration sandbox
3.Full copy sandbox.
1.Developer sandbox: It is just like configuration sandbox,it used for application development purpose.it is depends on existing application setup
2.Configuration sandbox: Used for for testing we can due production level testing on it with minimum data.
3.extract copy of production sandbox used for user level testing .
