As we know, Salesforce is built on the concept of multi-tenancy architecture i.e. customers use shared servers or resources. Therefore, the unit that contains all the resources like application, database, etc to run salesforce is known as “Salesforce Instance”. There are many instances distributed in various regions like North America(NA), Asia Pacific, EMEA, etc. For example: NA65, NA142, CS112, CS125.  Instances can be production instances like or non-production or sandbox instances. 

All the instances and their related statuses can be viewed at https://status.salesforce.com. It also shows all the ongoing incidents and ongoing maintenance of Salesforce. 

Sample screenshot of status of instance NA65 (taken at 1:30 PM, Pacific Time) from https:status.salesforce.com

Salesforce Organizations

Salesforce Organisation can be defined as the customer’s specific unit located on the salesforce instance referring to the data and metadata. 

We can easily locate the instance and org Id of our Salesforce Organization by navigating to “Company Information” after launching the set-up.

Salesforce Environments

Salesforce Environment refers to an organization that is used by a customer for a specific purpose. It can be used for development, testing, User acceptance testing(UAT), Integration or live environments. Environments are broadly classified into 2 types: Production and Non-production/sandbox environments.

Salesforce Sandboxes:

Sandboxes are largely used to develop, test and freeze the functionality before going live with the customer data thereby reducing the risk factors, minimizing the chances of breaking the existing processes and downtime of the business users and customers. Availability, usage and purchased status of various sandboxes can be viewed by following the below mentioned steps:

1. Click on the gear icon in the top-right corner of the page. It will launch the set-up
2. Search “Sandboxes” in Quick find or navigate to “Environments > Sandboxes” in left side bar and click it. 
3. It will display all the available sandboxes. 
   1. “New Sandbox” button can be used to create a fresh new sandbox
   2. Other options present inline with the name of the sandbox can be used for various actions like Deletion, Cloning, Refresh and Logging-in.

Note: Sandboxes can be viewed, refreshed, deleted and created only from Production Environments

Details of different types of Sandboxes:

1. Developer Sandbox
   
   It is used majorly for development (coding) and unit testing. On creating a new copy or refreshed copy of developer sandbox, only metadata is copied from production. It has the least data storage and file storage limit as compared to other sandboxes.
   
2. Developer Pro
   
   It is more and less similar to developer sandbox but with an increased limit of data and file storage. Therefore, along with development, it can be used for QA and integration purposes. Like developer sandboxes, only metadata is copied in these boxes as well. It has a data storage and file storage limit of 1 GB each.
   
3. Partial Copy
   

Unlike Developer and Developer Pro Sandboxes,  full metadata along with a small chunk of data is copied from the production. Sandbox templates are used to specify the data that needs to be copied from production. It has a data storage and file storage limit of 5 GB each.

4. Full Sandbox
   
   Full Sandboxes are the exact copy/replica of the production along with all its data. Given it contains full-fledged data, so it can be used for load testing, UAT, training the user, etc. The refresh interval of a full sandbox is of 29 days i.e. maximum as compared to other Sandboxes. That means it cannot be refreshed before 29 days of its last refreshed date.

Comparison Table of Sandboxes

Reference Screenshot from Salesforce Org