Spanish Textbook Differences?

Hi everyone, I plan on taking Spanish 2 over the summer at Ashworth Online College. However, the textbook they sent me, Realidades 2 from Prentice Hall, is not the one we use at school, which is the McDougal Littell En Espanol 2. I started to wonder if different textbooks teach different things, so today I borrowed the McDougal Littell book from a friend who is currently in Spanish 2. As I flipped through the pages of each book, I could see noticable differences in the vocabulary as well as how they teach the grammar.

My main question is, is there some sort of national curriculum in Spanish that textbooks have to follow? Will I be able to test into Honors Spanish 3 at the beginning of next year even though I learned different vocabulary than what people normally learn? Also, if any of you have any advice on what to do in my situation, please comment.Spanish Textbook Differences?
I have never used those books, but I have noticed differences in many math, english, and chemistry books. I am fluent in spanish so i don't have to learn it in school. You will NEVER find books that follow the same curriculum. They are all written by different people that explain things in a different way. Now, I know that when it comes to a language it should all be alike (since there is no other way around in grammar or spelling, like there is in math for example) But as you read them thoroughly you will see that at some point, you will learn the same rules for writing and speaking. one may have something in chapter 3 while the other book teaches it in chapter 17. But either way you will be fine, If you are not comfortable, maybe you should get both books and use the two at the same time. I have two different geometry boosk, for example, and it is so much better like this cuz i learn more and i find things to be easier in one book than the other.