Is a folktale a fairy tale?

The Brothers Grimm didn't actually write any stories; they just collected them from other people.

In 1812, the Brothers published a collection of 86 German Fairy Tales. They published a second volume of 70 fairy tales in 1814, which together make up the first edition of the collection, containing 156 stories. They wrote a two-volume work that included 585 German legends; these were published in 1816 and 1818. A book of 170 tales was published in 1819-22. Five more editions were issued during the Grimms' lifetimes,[14] in which stories were added or subtracted. The seventh edition of 1857 contained 211 tales. The Brothers also published the Kleine Ausgabe or "small edition," containing a selection of 50 stories expressly designed for children (as opposed to the more formal Große Ausgabe or "large edition").