Belarusian is a language spoken by people who live in the country of Belarus. It is like a secret code for people who can understand it. Just like how you can understand English, but not everyone in the world can understand it.
Belarusian has its own alphabet which is sort of like a special set of letters that are used only for this language. It includes some letters that English doesn't have, like the letter "Ў" which sounds like "oo" in "look".
When you talk in Belarusian, it can sound really different than English because the words can be pronounced differently. For example, instead of saying "Hello" like we do in English, you would say "Прывітанне" (pry-vee-tahn-nye).
Some people in Belarus speak Russian instead of Belarusian because they were educated in Russian or because their family has always spoken it. But it's important for people to learn and speak Belarusian so that the language does not disappear. It's like learning to ride your bike – it takes a lot of practice, but it can be really fun and rewarding!