The Zoras are an aquatic species that lives in and around the waters of Hyrule and many other lands. It is important to realize the division of this species in the two races of Sea Zoras and River Zoras.
Both are quite tall, their hands and feet are webbed and, as they spend so much time swimming, they are mostly in great physical shape looking lean and muscular (they can even swim up waterfalls). Being creatures of the water, Zoras are very sensitive to weather changes. Fire or ice can kill a Zora almost instantly. Magical ice can capture them, without harm though.
Zoras are amphibians making an unusual mix of fish and mammals traits. Their children are born from eggs, which are extremely sensitive, and have to be kept in very fresh, clean water. Also, for some reason, all eggs conceived at the same time need to be together to hatch. As newborns, the Zoras look like large, big eyed, tadpoles. It appears that Zoras never completely cease to grow (though in time they do come near to stopping) and can live for centuries.

The Sea Zoras are charming beings, with sparkling silver-azure skin (and scales near the gills on the sides of their abdomens) and dolphin-like tails that usually extend from the back of their heads. They usually have solid black eyes which grant them a better sight underwater; there are exceptions though, with eyes similar to those of the humans and heads shaped like a manta, traits common in the Royal Family. It is known that very few Sea Zoras have small real tails as well as other peculiarities. They can live outside water for a very long time (probably weeks), but of course they are most comfortable where it's damp.
Sea Zoras can talk just like Hylians, but their natural voices sound as if they are always underwater (likely because of water in their lungs). Although they don't usually wear clothes, they do sometimes develop a sense of fashion and put on something (armors are not unknown to Zora guards, who shape their helms to resemble their river cousins); also some of the Zoras decorate their bodies with tattoos and fish bones, possibly even cutting their fins in fashinable manners. The Zoras help the other species by keeping the waters clean and weaving the Zora Tunic, an item made of Zoran scales that allows to breath underwater.
Sea Zoras are powerful warriors using staffs and a fighting style they developed very similar to martial arts; aside from that, those with the blood of warriors can extend their razor-sharp fins and launch them like boomerangs. Finally, if a Zora knows magic, he or she can easily create a deadly electrical force field around his or her body, and truthfully, Zoras seem to have a very weak bioluminescence while in water.

As for the River Zoras, this hideous race has a monstrous appearance and attitudes that are even with it. Their scaly bodies can be either green or blue with bone structured fins and large, fanged, red mouths, they obviously emphasize the aquatic side of their "hybrid" traits as they resemble fishes rather than dolphins as the Sea Zoras do; still, they surprisingly have eyes like those of humans (supposedly because rivers are not as dep and dark as the depths of the sea).
It is believed that most of them know not how to speak, not properly at least. They live like savages in the wild, with no known form of settlings aside from gathering in their falls. River Zoras have no qualms in attacking anything edible they see, be it intelligent or not (incidentally giving all Zoras, including the Sea ones, a bad reputation). They usually shoot fireballs out of their mouths (another surprising peculiarity of their race) but can also hack at any prey with their claws and they are feared for leaving rivers to hunt on land when it rains.

Both Zora races are ruled by large kings. The river Zora King is particularly intelligent. The Sea Zora princess has the duty of feeding and caretaking a leviathan known as Lord Jabu-Jabu; their worshipped patron deity. The Sea Zoras held one of the three magical stones that could unlock the Door of Time, the Zora's Sapphire. This stone belonged to the princess of the Sea Zoras, and she was only allowed to give it to the person she was going to marry, like an engagement ring.
The Zoras are native of Labrynna, but as water moves all around the world so they do. During the civil war, the Sea Zoras swam up the waters of Hyrule and established themselves in the outpost known as Zora's Domain. Once peace was finally reached, the Zoras turned their Domain into a peaceful place; still, for a time, they chose to keep to themselves, and would only allow inside Hylians on official business from the royal family (or few very good swimmers taking the shortcut they made to Lake Hylia).
In the centuries to follow however, it appears that the barbaric River Zoras took back their place in the rivers of Hyrule and inherited even its coasts. Evidently the Sea Zoras chose to return to their homeland and eventually plan for a new domain in Holodrum.
The Zoras we've got records of in Termina were only Sea Zoras; almost the same as those in Hyrule. The main differences are in their politic and religion, for they don't seem to have a monarchy there, nor a patron deity. All of them are fans of a Zora band called the Indigo-gos.