There is an option to create instances of Collections using the
SHIFT+A keys. Locate the Collection Instance option to add an
instance of existing Collections.
As you can see from the list, you have multiple benefits by using
Collections in your projects. For that reason, it is important to not only
use them but assign meaningful names to each of the Collections. That
helps to identify what types of objects they hold.
Tip: You can also use Collections from the Add menu. If you look at the
bottom of the menu, you can create new instances from existing
collections pressing the SHIFT+A key.
2.6.1 Renaming objects
As you start to create objects in Blender, you will notice that their names
appear as a combination of object type and a numeric sequence. The
default Cube displays the name of "Cube," after adding another object of
the same kind, it receives the name of "Cube.001".
Unless you rename those objects, after a few hours of work, you might
have a scene filled with Cubes starting with "001" and going all the way
to "100". That is terrible for scene organization, and you will easily lose
control over the project.
To avoid losing control, keep in mind that each object in Blender must
have a unique name.
To help manage object names, you have multiple ways to quickly identify
the name of any selected object. When you select an object, look at the
top left corner. There you find the active Collection and the name of your
selected object (Figure 2.33).