can you get all your textbooks on your ipad?

So people have turned me to the iPad since I am returning to college after taking a year off telling me that this piece of technology can assist me in many ways. It can save me money in the long run since I can take notes on it and will no longer need to buy as much paper and other utensils, as well as keep all of my social media and e-mail accounts in one area, which is all fine and dandy. But the one thing I am most skeptical about is the thing I hear about being able to buy all of my textbooks on the iPad so that I don't have to buy the physical books themselves. Here is my question, is that true? Am I able to buy a textbook that is specific to one of my college courses no questions asked? I feel as though it would be nearly impossible to do that. This would be one of the primary reasons I buy the iPad, is to not have to carry around all those books all the time along with different binders for notes and stuff. Please let me know if this is a true statement. It would be awesome if I could buy all of my semesters books on the iPad and only have to carry that around! Thank you!

Sincerely,

Chase