Scythian languages were spoken by a group of people called the Scythians who lived a long, long time ago in the area around modern-day Russia and parts of Central Asia. You know how you speak a language at home, like English or Spanish, and then you might learn a different language in school? Well, Scythian was like the language that the Scythian people spoke at home.
Scythian was actually a group of different languages that were spoken by different groups of Scythians. Just like how different people speak different languages in different parts of the world, the Scythian people from one area might speak a slightly different language than the Scythians from another area.
Nowadays, nobody really speaks Scythian languages anymore because the Scythians aren't around anymore. But people can still study the language and learn about it to understand more about the Scythian people and their culture.