What is the brown fox jumps over the lazy dog?

"The quick brown fox jumps over the lazy dog" is a well-known pangram which contains all the letters of the English alphabet. It is often used as a typing exercise to practice using all the letters. The phrase has been used in many contexts, including in typography, cryptography, and literature. The origin of the phrase is unknown, but it is believed to have been first used in a 19th-century book on typography.