An encyclopaedia is an extensive compilation of information. It may be general, containing information about a large amount of different topics, or it may focus on a particular subject matter such as medicine or engineering. Some encyclopaedias concentrate on offering information from a certain cultural or national point of view. An encyclopaedia may be arranged according to headings, either in an alphabetical order or by subject matter. Alphabetical order is the most common, particularly in general encyclopaedias. Articles in encyclopaedias may vary in length from a few sentences to several pages, depending on the encyclopaedia.

A dictionary is a kind of reference work that presents words, usually in alphabetical order, chosen according to some particular criteria. In monolingual dictionaries, explanations are given for the words; other dictionaries offer foreign language equivalents of the words.

A handbook is a kind of reference work that presents central information from a particular subject field. Handbooks are useful sources of factual information, which provide help in solving practical problems. They may contain for instance tables, constants and standards, and often they offer references to other sources of information.

A table is a numerical or other such presentation of information in a list format, usually using several columns (e.g. mathematical tables, physics and chemistry tables, statistics). It is important to know which books of formulae and tables one should be using. It is also useful to consider how reliable the information in the tables is.