Grantha script is a kind of writing that was used a long, long time ago in a place called South India. People would use special little symbols and lines to write down words and stories in a book.
The special thing about Grantha script is that it's not like the writing we use today. It's different and unique, and it takes a lot of practice to learn how to read and write it.
Think of it like this - when you were little, and you learned how to write your letters for the very first time, it was hard, right? You had to practice and practice until you could write them all perfectly.
That's kind of like what Grantha script is. People in South India would practice and teach each other how to write and read it, so they could write down important information and stories from their culture.
Nowadays, we don't use Grantha script that much anymore, but we can still see examples of it in old books and documents. It's an important part of South Indian history and culture, and it's something that people can still learn and appreciate today.