In general, the Roma can be divided into categories in several different ways, because the identification Rom is only an aggregate name for a number of ethnic groups with a common origin, language and many common cultural features. The term Rom means Man in Romany, a term approved in 1971 by the international Romani Union.

Categorizing the Roma living on the territory of the former Czechoslovakia is difficult, because their composition was entirely changed after the Second World War. Before the Second World War, in the Slovak Republic there were the Slovak Roma (speaking the Slovak dialect of Romany, the most numerous group) and the Hungarian Roma (speaking the Hungarian dialect of Romany). In Bohemia and Moravia, there lived the Czech-Moravian Roma (speaking the Czech-Moravian dialect of Romany, about the same number as the Hungarian Roma) and, in the Sudeten lands,the German Roma (speaking the Sinti dialect of Romany, the least numerous group). Throughout the whole area of Czechoslovakia migrated the less numerous groups of Wallachian Roma, who speak the Wallachian dialect of Romany.

After the Second World War, the Czech-Moravian and German groups of Roma were almost completely wiped out and the Slovak Roma were moved en masse - to the homes of the Sudeten Germans, or, through the so-called "dispersion", to the industrial areas of Bohemia and Moravia as a light, unskilled work force. After their migratory way of life was outlawed in 1959, the Wallachian Roma were also settled in Bohemia.

The Roma in the former Czechoslovakia, before the banning of migration in 1959, were divided into migratory, semi-migratory, and settled groups. In the Czech lands, the migratory or semi-migratory groups were the Wallachian Roma, who came to the area from the modern-day Rumania - consisting of Wallachia and Moldavia - after the abolishment of slavery/serfdom there. Many of them lived a migratory life until it was outlawed in 1959. Unlike many other modern Roma, they've preserved their tongue (the Wallachian dialect) and held on to their customs. They're very closed and don't allow any foreigners within their company, and contacts between the Wallachian Roma and the settled ones are very uncommon. Semi-migratory groups kept only temporary residences, in which they normally spent just the winter months. Through most of the year, they moved about in their characteristic wagons - shiatras, covered with canvas and pulled by horses - or wandered by foot and camped in tents. Nomadism was practiced in concert with their livelihood (most often horse trading), which didn't usually provide them with all they neeed to exist, so they frequently "complemented" their income by various, less socially-acceptable means.

The non-migratory Roma, settled in the Czech lands by Maria Theresa, made their living through their trades or through small services to the gadje (non-Roma) - such as farmers from the villages - near where they lived in their characteristic residential units, or camps (which survive to this day, especially in eastern Slovakia, where they number almost 300).

The Roma can also be classified by their trades, and the performing of certain trades was connected to a certain social status, the best position belonging to musicians. The Roma brought many of their professions along with them from India, in particular the trades of blacksmithing, basket weaving, trough digging, horse trading, the production of bricks and brooms, and sharpening knives. The Wallachian Roma traditionally specialized in horse-trading, and the women in fortune-telling

Among themselves, the Roma are divided into city-dwelling and country-dwelling inhabitants.

The Roma population is scattered among the non-Roma population either in certain neighborhoods or streets in the cities or in suburbs (city-dwelling), or in separate Romani camps on the margins of rural communities (country-dwelling). These country Roma have preserved much of their culture and traditional way of life thanks to their relative isolation from other peoples, while the Roma living in the cities among the non-Roma have come closer to the surrounding society in certain areas of economic life and in some aspects of social behaviour.

Another perspective by which the Roma are divided internally is in the adherence or non-adherence to various traditions and rules,according to which Roma are classified as clean (zuze Roma) or dirty (degesa). Every group or family considers something different as dirty or inferior, however. Among the Roma considered unclean are those, for instance, who eat horse meat (the horse was almost a sacred animal among the Roma) or meat scraps, or who broke the group endogamy and married their daughter to someone outside the group. Families considered unclean as a result of these classifications would be isolated from other Roma.

According to the time of arrival to a certain area, to a town or village, the Roma could also be divided into the already settled and the newly arrived.

The divisions by wealth are most familiar to us, as everywhere in the world, in every society, people are divided into rich and poor. While the poorest are considered the Roma from the camps in eastern Slovakia, the majority of Roma are by most definitions socially needy. The richest Roma have traditionally been musicians, first performing in the courts of nobles, later forming a special class of urban cafe musicians. The Wallachian Roma, who were among the poorest groups in the 1950's, are today, as a result of various forms of "business", among the richest of the Roma. Contact between the settled Roma and the Wallachian Roma is minimal.

In these classifications, the level of familiarity with the Roma is important, but the most common is categorizing by the level of assimilation - thus into proper or respectable Roma and the improper/non-respectable, and this is connected to the divisions by social class as well.

Non-Roma also classify the Roma according to their external appearance. The most visible difference is between the "light" and "dark" Roma. Wallachian Roma have lighter pigmentation and lighter hair, and can most often be seen in the clasic Romani attire - long, colorful skirts, three-cornered scarves on their heads or shoulders. Gold has an immense value for them, and so they can more frequently be seen wearing rings, earrings, necklaces, bracelets and even gold teeth than any other Roma. As a nomadic people, they weren't able to put their money into immovable property, so they put it into gold. Gold has another significance for them, however. The Wallachian Roma believe that the gold jewelry they wear acts as protection against disease. They also speak Romany - the Wallachian dialect - among themselves more often than other Roma.

On the basis of dialect research and sociological data, the Linguistics section of the Centre de recherches tsiganes at the Universite Rene Descarte arrived at the following divisions in the Romani language:

I. Romanyin the original sense,which is spoken by the majority of Roma around the world, is further divided into three groups of dialects. These dialects have the basic Romany vocabulary and, except for loan-words from contact languages for modern life (television, truck-driver, etc.), there's a high level of comprehension between them.

The Balkan-Carpathian-Baltic group is divided further into the Old Balkan, Carpathian, and Baltic subgroups, The Gurbet-Cerhan group, which is only spoken in the Balkans, and The Kalderash-Lovar group, which is the most geographically widespread, from the Urals to California and Beunos Aires.

II. Sinto-Manush dialects, are divided into Carpathian and Baltic subgroups and contain a large number of loan-words from Germanic languages. Even the morphology (system of word structure) of these dialects has undergone substantial changes, so that comprehension between speakers of these dialects and the preceeding ones is minimal.

III. Local dialects of other languages containing Romani words, are spoken by groups of Roma who lost their own language in efforts toward assimilation. The Spanish gitanos, for example, were persecuted in the 17th and 18th centuries and punished for using Romany, so that the Calo dialects have Romany words but Spanish grammar. Similar situations exist in Great Britain and some regions in Rumania. These dialects are completely incomprehensible for Roma of the other dialect groups.

From all these divisions, it's evident that the Roma are not and never were a homogeneous group, and therefore it would be correct to differentiate among them and not to make generalizations about them.