Bitcoin is virtual currency, real money easy to invest. Real money has no transaction fees. But i like to prefer digital currency to make transactions. I like invest on bitcoin because bitcoin cost is very high 
There is a very big difference between these two paper money is also useful for every one because when there was no concept of digital currency so everyone was using paper money and now a days everything is going to digital and bitcoin is also a digital currency bitcoin make a life easy and fast for every one and it connect world together you can also learn a lot of things from here because bitcoin is the best for earning in a short time.