Nesting has a very broad semantic field.  The term is commonly used in biology/zoology, information technology as well as in common parlance.  Within an information technology context, both programmers and database designers and admins use the term nesting.

Nesting in IT generally refers to activities where information is organized in layers or objects contain other similar objects. Functions can be nested within each other in a spreadsheet, for example. Word processing apps typically also let you nest one document inside another document.

Furthermore, nested virtualization or recursive virtualization means running a virtual machine within another virtual machine, and a nested statement is a SELECT statement that contains at least one subquery. The nested set model is also one of several ways to structure hierarchical queries in SQL database.

Idera’s SQL Admin Toolset allows you to nest server groups to better organize your SQL Server instances. Nesting is especially helpful if you need to organize several small server groups or if you need to filter instances by various properties, such as location, data type or data source.  The SQL Admin Toolset help guide explains how nesting works: “If you select a nested server group when running one of SQL admin toolset tools, the tool acts on all the instances belonging to the selected server group as well as any instances belonging to the child server groups.”

For example, you could nest payroll or HR databases by location at your major regional offices, and when you select the payroll or HR server group, the tool would act on all of the server instances belonging to the nested regional offices.