I really like that it allows you to install more than one operating system too.
It runs just like any other program would on a mac, and acts as a virtual machine, allowing you to install other operating systems with the program. It also meant I couldn't access both operating systems at the same time.
Before I discovered Parallels Desktop for Mac, in order to use windows I had to 'dual boot' my mac which I found to be quite time consuming (having restart my computer anytime I wanted to switch). Pros: This is THE software to have if you use a mac as your main computer but also need to use software that can only run on a windows operating system.