Explain two differences between freeware,shareware and open source software?

Shareware is try before you buy, typically only some of the features of the program are available more like a demo. Where as freeware is a program that is free to use any where, and open source is free software that you also have the source code available to edit, or modify as you wish. Most people don't need to edit the source code so by far and large freeware and open source are one in the same.