As mentioned, Magento Commerce is an open source platform. You will also need to understand what open source is before you choose a product of this type. Think about most types of software that you could purchase for your computer. Have you ever noticed just how specific they are about what other programs they will work with and on what types of computers they will work? Open source is a different idea that involves the belief that you should not be tied down to this.
Instead, open source means that software can work on almost any platform and can easily be redistributed. When you choose open source software, you will have an extensive amount of freedom when it comes to use than you would with anything else. Because of this, many people feel that there is a definite advantage to using software of this type.