Every database professional should know how to manage SQL instances, which are separate instances of the SQL Server Database Engine that run independently of one another. An instance can contain multiple databases, and each database can have multiple users. Instances can be used to isolate different applications or groups of users, or to improve performance by dedicating an instance to a specific task.
There are many reasons why you might need to check SQL instances. For example, you might need to check the status of an instance to see if it is running properly. Or, you might need to check the properties of an instance to see what settings are configured.