They are black with white stripes. These stripes are typically vertical on the head, neck, forequarters, and main body, with horizontal stripes at the rear and on the legs of the animal. The zebra crossing is named after the zebra's white on black stripes.

Originally, most zoologists assumed that the stripes acted as a camouflage mechanism, while others believed them to play a role in social interactions, with slight variations of the pattern allowing the animals to distinguish between individuals. A more recent theory, supported by experiment, posits that the disruptive coloration is an effective means of confusing the visual system of the blood-sucking tsetse fly.
Alternative theories include that the stripes coincide with fat patterning beneath the skin, serving as a thermoregulatory mechanism for the zebra, and that wounds sustained disrupt the striping pattern to clearly indicate the fitness of the animal to potential mates.

There are four extant species, as well as several subspecies. Zebra populations vary a great deal, and the relationships between and the taxonomic status of several of the subspecies are well known.

The Plains Zebra (Equus quagga, formerly Equus burchelli) is the most common, and has or had about twelve subspecies distributed across much of southern and eastern Africa. It, or particular subspecies of it, have also been known as the Common Zebra, the Dauw, Burchell's Zebra (actually the subspecies Equus quagga burchelli), and the Quagga (another extinct subspecies, Equus quagga quagga).

The Mountain Zebra (Equus zebra) of southwest Africa tends to have a sleek coat with a white belly and narrower stripes than the Plains Zebra. It has two subspecies and is classified as endangered.

Grevy's Zebra (Equus grevyi) is the largest type, with an erect mane, and a long, narrow head making it appear rather mule-like. It is an inhabitant of the semi-arid grasslands of Ethiopia, Somalia, and northern Kenya. The Grevy's Zebra is one of the rarest species of zebra around today, and is classified as endangered.

Although zebra species may have overlapping ranges, they do not interbreed. This held true even when the Quagga and Burchell's race of Plains Zebra shared the same area. According to Dorcas McClintock in "A Natural History Of Zebras," Grevy's zebra has 46 chromosomes; plains zebras have 44 chromosomes and mountain zebras have 32 chromosomes. In captivity, Plains Zebras have been crossed with mountain zebras. The hybrid foals lacked a dewlap and resembled the Plains Zebra apart from their larger ears and their hindquarters pattern. Attempts to breed a Grevy's zebra stallion to Mountain Zebra mares resulted in a high rate of abortion.