Cola is a sweet, fizzy soft drink flavored with ingredients like vanilla, cinnamon, citrus oils, and originally the kola nut. The two most famous colas are Coca-Cola and Pepsi, both invented in the late 1800s and now sold worldwide.

When someone orders “a cola” at a restaurant, they usually mean one of these dark, bubbly drinks served cold over ice. The original cola recipes included extracts from the kola nut, which contains caffeine, though modern colas usually get their kick from added caffeine instead.

Cola has become so popular that people often use brand names like “Coke” to mean any cola, or even any dark soft drink. If you're at a friend's house and they offer you cola, you might get Coca-Cola, Pepsi, or a store brand, but they'll all taste similar: sweet, fizzy, and slightly spicy from the blend of flavors.

The word can also describe the color: cola-colored means a dark reddish-brown, like the drink itself. Scientists studying rivers or lakes might describe water as cola-colored when it has that same dark tint from natural materials like leaves and soil.