Hey there, kiddo! Have you ever heard different people speaking Spanish but they sound a bit different from each other? Well, that's because there are many different Spanish dialects and varieties!
Think about it like this: have you ever sung "Happy Birthday"? When you sing it with your family, do you all sing it the same way? Probably not! Some people might sing it a bit faster or slower, some people might sing it in a lower or higher voice, and some people might sing it with different accents.
It's the same with Spanish! Different people in different parts of the world speak Spanish in different ways. Some people might use words that others don't, or they might pronounce words differently. They might even have different grammar rules!
For example, in Spain they say "vosotros" instead of "ustedes" when they want to refer to a group of people (like saying "y'all" instead of "you guys" in some parts of the US). In Argentina, they might use the word "vos" instead of "tu" to say "you". And in some parts of Mexico, people might say "sh" instead of "s" (so "gracias" sounds like "grashias").
These differences in how people use Spanish are called dialects and varieties. They don't make one type of Spanish better or worse than another - they're just different ways of speaking that have developed over time in different places.
In fact, you might even notice different dialects and varieties of Spanish in your own city or town! Maybe your friends' families use different words or pronunciations than your family does. It's all part of the rich diversity of language and culture!