Production and Sandbox Environments ?

Production:

We should not make coding changes in production since end-users are using the application from production environment.

Production URL:  login.salesforce.com

 
Sandbox:

         Sandbox is a copy of your production organization. You can create multiple copies of your organization in separate environments for different purpose such as development, testing and training, without compromising the data and applications in your production organization.

Sandbox URL: test.salesforce.com

        Generally, in each phase of project requires different environments like during construction phase there are chances to multiple teams will work on development in this case each team requires their own sandboxes for development.

         After the construction period we need one common testing environment, during training period training team requires separate environment for training purpose and before going to production one staging environment required. So for each phase different environments required.

 

Development Life Cycle:

1. Create development environments.
2. Develop using salesforce web and local tools.
3. Create testing environments, including UAT and integration.
4. Migrate changes from development environment to integration environment.
5. Test.
6. Migration changes from integration environment to UAT environment.
7. Perform user-acceptance test.
8. Migrate changes from UAT environment to staging environment.
9. Replicate production changes in staging environment.
10. Schedule the release.