Dictionaries are either monolingual works with definitions of words, or bilingual for translation purposes. Dictionaries can be generic, or specific to a certain field with special terminology.
Encyclopedias and handbooks offer systematic references of different fields with basic and research information in summarized form. They can be either multidisciplinary or specific to a certain field.
Reference works are intended as resources from which information can be retrieved quickly. They can be used to get a general idea of the desired topic and terminology, and for checking individual facts.