Vatteluttu is an ancient Indian script that people used to write down things long, long ago. It's like the alphabet you know, but different because instead of letters like A, B, C, and D, they had little marks that stood for sounds in their language.
These marks were put together in different ways to make words and sentences. The people who knew how to read and write vatteluttu were very important because they could communicate things in writing and keep records of important things that happened.
Even though not many people use vatteluttu anymore, it was an important part of India's history and culture. Just like how children learn to read and write in school today, people long ago learned to write using vatteluttu.