"The quick brown fox jumps over the lazy dog" is a pangram (a phrase that uses all the letters of the alphabet) that has been used to test typewriters and computer keyboards because it is coherent and short. It was known in the late 19th century, and Baden-Powell's book Scouting for Boys (1908) used the phrase as a practice sentence for signalling. The earliest known published use of the phrase is in the January 10, 1903 issue of Pitman's Phonetic Journal, where it is referred to as "the well known memorized typing line embracing all the letters of the alphabet".
Many minor variations exist, including replacing one of the "the"s with an "a". Although it is the most popular, many other pangram sentences are shorter, such as "The five boxing wizards jump quickly."