So kiddo, the Royal Spanish Academy is like a group of really smart people who are in charge of making sure Spanish words are spelled and used correctly.
They have a big important book called a dictionary where they write down all the words in Spanish and what they mean. When people have questions about how to say something in Spanish or what a word means, they can look it up in this book.
These smart people also make rules for how sentences should be structured and how words should be used in Spanish. This helps everyone who speaks Spanish to communicate clearly and effectively.
The Royal Spanish Academy has been around for a long time, over 300 years! And they keep updating their dictionary and rules to keep up with changes in the language.