Sandboxes

A sandbox is similar to the dev, test, and stage environments in other technology stacks. They are mainly used for the development of Salesforce applications and testing of newly developed features. We do not want to make changes in the production environment directly without testing it thoroughly. So we need these different types of sandboxes; depending on what we can do with them, we can choose which one to use. Some sandboxes only have metadata from production, and some may have both metadata and data in them. Sandboxes also vary in size. Let's see how they differ.

A sandbox is used to develop and test applications. Depending on the type of sandbox you use, it may also include a copy of the data from your production organization. A sandbox is completely isolated from the production organization, so any changes the developers make won't compromise the data, applications, or day-to-day activities of the other users in the production organization. It is ideal for developing complex customizations to minimize risks.

There are various types of sandboxes:

• Developer: A Developer sandbox is used for development and testing. It provides a separate environment for coding and testing changes done by developers. According to Salesforce standards, one Developer sandbox should be used by one developer for coding at a time, but it is possible for multiple developers to log in at a time. However, a Developer sandbox does not keep track of changes done in it so there are lots of possibilities that developers may overwrite each other's code. A Developer sandbox has a copy of metadata from production. It does not contain data.
• Developer Pro: A Developer Pro sandbox is also used for development and testing purposes, but this sandbox comes with increased storage size. Because of the increased storage size, this sandbox can handle more development workloads and can be used for data load and integration testing. 
• Partial Copy: A Partial Copy sandbox contains all the metadata from your production organization, and it also contains a sample of the production organization's data, which is defined in the sandbox template while creating a Partial Copy sandbox. As this sandbox contains sample data, it is mainly used for testing purposes. We can use a Partial Copy sandbox for development, testing, and even for training purposes. Most people do not recommend them for load testing purposes.
• Full: A Full sandbox is a replica of your production organization. It contains all the metadata and data from the production organization. It contains all data, which includes records, attachments, and so on. You can use sandbox templates to decide which data to copy from the production organization to the Full sandbox, depending on which testing operations you want to perform. A Full sandbox can be used for many purposes and supports load testing, performance testing, and staging. It is difficult to use a Full sandbox for development because it needs a long refresh interval.