What is the difference between a disjunctive and a conjunctive facet?

Regular (or Conjunctive) facets allow to filter by one value of the attribute (e.g. 'music'). They are most of the time displayed with links.

Disjunctive facets allow to filter by one or multiple values of the attribute (e.g. 'Movies & TV Shows' OR 'Printer Ink'). They are most of the time displayed with checkboxes.