World Building

Nomads have herds of herbivore animals. The mongols and native americans have horses, the Tuareg have goats and camels, the Sami people have raindeer, other african nomads like the Massai have cattle.
Nomads need to move periodically because their herds won't find enough food in one place year around.
Since nomads live in areas of scarce vegetation, almost all of them use the dried excrement of their animals as fuel for cooking.
To move, nomads need movable accomodations. These are typically tents, but have different shapes and are made of different materials, depending on the environmental conditions and the available materials. They are usually in a very simple, yet stable way and can be erected and disassembled within half an hour.
They have little possessions, because everything has to be moved.
Nomads care for their animals because they secure their life. The female animals are milked to produce dairy products, the meat is eaten, the skins are worked into clothing and even the bones are used as tools.
Having big, ridable animals aids the nomad lifestyle, but is not neccessary for it.
Their animals, the nature and environment usually play a big role in their traditions and religions. They are so dependent on the weather that they often can "read" the atmosphere and predict the weather.