A pamphlet is a small book without a hard cover or binding). It can be made up of a single sheet of paper that is printed on both sides and folded in half, in thirds, or in fourths (called a leaflet).
It can also be made up of a few pages that are folded in half and stapled at the crease to make a simple book. In order to count as a pamphlet, UNESCO requires the pamphlet to have 'at least 5 but not more than 48 pages' not including the cover page; a longer item is a book.
Pamphlets can contain anything, it may include information on kitchen appliances, instructions as well as religious and political ideas. Pamphlets have been very important in history, publishing a lot of pamphlets can help spread ideas, for instance during the Russian Revolution pamphlets were used to influence people. Pamphlets are also very important in marketing as they are cheap to produce and can be distributed easily to customers.