Ethnicity, Language, & Religion of Ukraine
WARNING: Ukraine is politically unstable, please read this travel warning before going!
Ethnicity
The people of Ukraine are primarily ethnically Ukrainian, but there's a significant Russian minority consisting of nearly a quarter of the population. The Ukrainians are Slavs, very similar ethnically to the Russians and Belarusians. There are also ethnic people from nearly all neighboring countries (including Belarus, Poland, Romania, Moldova, etc.) and there is a return of many Tatars, who historically lived in the Crimean Peninsula, but were deported during Soviet times (primarily to Central Asia) and only recently began returning.
Language
Ukrainian is the only official national language in Ukraine, but this was not the case under Soviet rule, which demanded the people speak Russian in order to secure good jobs and connections. For this reason, nearly everyone today still speaks Russian, while many of the ethnic Russians don't learn Ukrainian, making Russian the de facto language of communication. This is slowly changing as much of the young generation is learning western European languages over Russian, in particular English. In the western part of Ukraine many young people today don't speak Russian, while in some areas (Odesa, Crimea) Russian is still the dominant language. Ukrainian is an eastern Slavic language, most closely related to Russian and Belarusian.