Unclear about useage of mu-plugins


On my second install, so this time I am going thru step by step. Noticed some inconsistent info between the usage, and the manual.

In the manual, it says that some plugins must be uploaded to the mu-plugins folder, and uses domain mapping as an instance of this rule. In the usage for domain mapping, it says to upload this plugin to the normal plugin folder.

I ask this because I have several plugins, and not one in the mu-plugins folder. Is there a list of plugins I need to move over to the mu-plugins folder? Or is it okay for it to be in the normal folder so long as the given plugin is network activated?

Thanks in advance!