Okay, kiddo. So, in long-long time ago, people in ancient Rome spoke Latin. However, over time, the way they spoke Latin changed and other people started to speak it differently. This is called Vulgar Latin. It was kind of like when you and your friends say some words differently than your teachers do.
Vulgar Latin was the language that regular people spoke in their everyday lives, whereas regular Latin was more formal and used by important people in more official settings.
As Vulgar Latin evolved, it became the basis for many of the modern languages we have today. For example, Italian, Spanish, Portuguese, French and Romanian all came from Vulgar Latin!
So basically, Vulgar Latin was the every-day version of Latin, and it helped give rise to many of the languages we use today. Pretty cool, huh?