Okay kiddo, so a long time ago, there were people who lived in an area that we now call India and Iran. They spoke a language called proto-Indo-Iranian.
Now, this language was really important because it helped to create many other languages that people still speak today. For example, Hindi, Persian, and even English are all related to proto-Indo-Iranian.
But you might be wondering, how do we know about this language if nobody speaks it anymore? Well, smart people called linguists study ancient texts and words from these regions and figure out how they were pronounced and used. It's kinda like being a detective and figuring out clues to solve a mystery!
So, proto-Indo-Iranian is like the grandparent language of various languages we speak today. It's fascinating to learn about where our words come from and how they evolved over time!