I am refering following URL
Buy VMware vRealize Automation, Cloud Automation Software | United States
it says
vRealize Automation is included as part of vCloud Suite or vRealize Suite. vRealize Automation is also available on a standalone basis, priced per managed system in packs of 25. vRealize Automation Development Kit is available as an add-on via a perpetual license on a per vRealize Automation Instance basis.
I am struggling to understand difference between things mentioned in highlighted text.
In short I need some better understanding of vRA licensing.