A pretzel is a crispy snack or a soft, baked good. Both kinds of pretzel usually have a distinctive, knot-like, twisted shape.
Pretzels are salty snack foods, so you'll find them alongside potato chips and popcorn in the grocery store. Pretzels that come in a bag are crisp and small, while the soft kind is often sold from food carts and topped with mustard. The pretzel was originally a German invention, so it makes sense that the word comes from the German Brezel, which is rooted in the Medieval Latin brachitella, "biscuit in the shape of folded arms."