The quick brown fox jumps over the lazy dog is the most popular English language pangram; a sentence which contains all letters of the alphabet.
Pangrams are usually used for testing typewriters and fonts in order to see if they display all letters of the alphabet properly.
The earliest appearance of “the quick brown fox jumps over the lazy dog” was published in The Boston Journal in an 1885 article, titled “Current Notes” where it was cited as the favorite practice sentence of writing teachers.
With the spread of typewriters, the sentence grew popular among those who wished to improve their typing.
“The quick brown fox jumps over the lazy dog” was seen in the first message sent on the Moscow-Washington hotline in 1963.
With the rapid development of computer technology, the sentence started appearing in digital contexts, as a way of testing font samples and computer keyboards.
It became so popular, that Microsoft Word has a command to auto-type the sentence.
The sentence was first defined on Urban Dictionary in 2004.