Ductless mini-splits aren't ducted. (These are the type most are familiar with, the ones with a large air handler up on the wall or in a ceiling cassette.) However, mini-split just means that the condenser and evaporator units are separate ("split") and are smaller capacity ("mini") than a traditional central air system (which are also "split").

There are ducted mini-splits in addition to ductless mini-splits.