Computer
Refers to the server that hosts a SQL Server, this maybe a physical or virtual server.
Database
A database is a data structure that stores organized information. Most databases contain multiple tables, which may each include several different fields. For example, a company database may include tables for products, employees, and financial records. Each of these tables would have different fields that are relevant to the information stored in the table.
Instance
Also known as SQL Server or SQL server instance. SQL Server supports multiple “instances” or installations on the same host computer. Each instance runs independently from all others and has its own set of installation code, configuration parameters, system and user databases, memory allocation, and security configuration.
Location
The location refers to the physical or geographical location of an instance, such as Houston for example. SQL Admin Toolset tools allow you to add this information on the instance that you are registering so you can later filter and get details or graph views for the instances belonging to this location.
Owner
The owner refers to the user whom the instance belongs to. When you register an instance, Idera recommends that you register the instance owner, so later you can easily get information from this owner and his/her respective instances.