International scientific vocabulary is a way for scientists from all over the world to talk to each other using the same words, no matter where they live or what language they speak.
Think about it like this: if you were playing a game with a friend who speaks a different language than you do, it might be hard to explain the rules if you're using different words. But if you both agree to use a common vocabulary, like saying "kick the ball" instead of "boot the orb," then you can communicate more easily.
In science, it's even more important to use a common vocabulary because scientists are often studying things that are hard to see or understand, like atoms or DNA. So, to make sure that everyone knows what they're talking about, scientists use specific words for different things.
For example, if a scientist wants to talk about the part of a cell that makes energy, they'll use the word "mitochondria," no matter what language they speak. And if they want to talk about the process by which plants turn sunlight into food, they'll use the word "photosynthesis," even if their native language has a different word for it.
By using the same words, scientists can collaborate with each other more easily, share their research more broadly, and build on each other's work to learn even more about the world around us.