A reference work is a compendium of information, usually of a specific type, compiled for ease of reference. That is, the information is intended to be quickly found when needed.

The writing style used in these works is informative; the authors avoid use of the first person, and emphasize facts. Indexes are commonly provided in many types of reference work. Most are updated as needed, typically with a new edition each year.

In libraries, these works are typically not allowed to be checked out.

Examples:

• Almanac
• Atlas
• Citation index
• Concordance
• Dictionary
• Directory or Lexicon (the latter generally provides more grammatical analysis)
• Encyclopedia
• Gazetteer
• Handbook
• Mathematical tables
• Periodical index
• Scientific table s
• Thesaurus

See also: Wikipedia's list of reference tables