Slavs
Slavs can be further grouped by religion. Orthodox Christianity is practiced by the majority of Slavs. The Orthodox Slavs include the Belarusians, Bulgarians, Macedonians, Montenegrins, Russians, Serbs, and Ukrainians and are defined by Orthodox customs and Cyrillic script as well as their cultural connection to the Byzantine Empire (Serbs also use Latin script on equal terms). Their second most common religion is Roman Catholicism. The Catholic Slavs include Croats, Czechs, Kashubs, Moravians, Poles, Silesians, Slovaks, Slovenes, and Sorbs and are defined by their Latinate influence and heritage and connection to Western Europe. There are also substantial Protestant and Lutheran minorities especially amongst the West Slavs, such as the historical Bohemian (Czech) Hussites.
Slavic languages
The tripartite division of the Slavic languages does not take into account the spoken dialects of each language. Of these, certain so-called transitional dialects and hybrid dialects often bridge the gaps between different languages, showing similarities that do not stand out when comparing Slavic literary (i.e. standard) languages. For example, Slovak (West Slavic) and Ukrainian (East Slavic) are bridged by the Rusyn language/dialect of Eastern Slovakia and Western Ukraine. Similarly, the Croatian Kajkavian dialect is more similar to Slovene than to the standard Croatian language.