What is the difference between a putsch and a coup?

Answer 1

The difference is very slight; coups d'etat are by definition successful whereas putsches are not necessarily successful. Both involve a sudden and usually secret and violent attempt to overthrow a government.

One of history's most famous putsches was Hitler's Beer Hall Putsch, which occurred in the 1920s in Munich. Hitler was imprisoned for his role in this putsch, and he went on to write Mein Kampf during his imprisonment. Likely because the Beer Hall Putsch is by far the most famous putsch, the term "putsch" usually refers to an unsuccessful attempt to overthrow a government, although a "putsch" could be a successful overthrow according to the term's dictionary definition.