Hellenic languages are the fancy name given to the languages spoken in ancient Greece. You might have heard of Greece – it's a beautiful country with lots of water and big buildings that people used to build (and still build) to worship their gods.
Long long ago, people in Greece didn't speak English or Spanish or any of the other languages that people speak today. They had their own way of speaking, and that way of speaking is called Hellenic. Hellenic is not one language, but a group of languages that are related to one another, kind of like how you have cousins who are related to you but not exactly like you.
Some of the most famous Hellenic languages are Ancient Greek and Modern Greek. Ancient Greek was spoken a long time ago by philosophers like Socrates, Plato, and Aristotle. They talked and wrote about all sorts of things, like science, math, ethics, and politics. Their ideas were so good that people still read and learn from them today.
Modern Greek is the language that people speak in Greece now. It's a little bit different from Ancient Greek because it has changed and evolved over time. People still learn about Ancient Greek though, because it's an important language and has influenced so much of our history and culture.
In summary, Hellenic languages are the group of languages that people in ancient Greece spoke, like Ancient Greek and Modern Greek. They are important because they have had a big impact on our world and history.