Hi Olena! That's a great question. We use "historic" for something important and influential that happened in the past. It's mostly used for events. For example, you could say "World War II was a historic event" because it was important and had a huge impact on the history of the world.
On the other hand, we use "historical" for anything from the past. For example, if you see a building that was constructed in 1820, you could say "that's a historical building".
I hope this helps! :)