Difference between 'Preferred IUPAC Name' and 'Systematic IUPAC Name'
The problem with systematic IUPAC names is that many compounds can have more than one systematic IUPAC name. A compound may be named correctly in two or more ways in accordance with the several methods recommended by IUPAC. Thus, asking for the systematic IUPAC name does not make sense for such compounds.

Therefore, current IUPAC recommendations (currently only for organic chemistry) include the definition of a preferred IUPAC name (PIN), which is the name preferred among two or more names generated from two or more IUPAC recommendations including also the many retained names.

Whether the preferred IUPAC name is also actually preferred by chemists cannot be generalized and depends strongly on the context.