When you place fillings like meat, cheese, or vegetables between two slices of bread, you've made a sandwich. It's one of the world's most popular meals because it's portable, customizable, and doesn't require utensils. You might pack a peanut butter and jelly sandwich for lunch, or order a turkey sandwich at a deli.

Today, sandwiches come in countless varieties: grilled cheese, club sandwiches, submarine sandwiches (often called subs or hoagies), and open-faced sandwiches with just one slice of bread. The word can also be a verb: when you get sandwiched between two taller people in a photo, you're squeezed in the middle. Or you might sandwich your homework time between soccer practice and dinner, fitting it snugly between two other activities.