The first two of these are classified for running software on computers (i.e., actually using the computers), while the last one is about developing the software in the first place.
As HP's first business-class AiO with an optional non-glare touchscreen, the beautifully redesigned HP EliteOne AiO delivers an Elite user experience with an elegant thin design, powerful processors, multi-faceted security, and engaging collaboration capabilities
HP 255 G2 - A series A4-5000 / 1.5 GHz - Windows 7 Pro 64-bit / Windows 8.1 Pro downgrade - pre-installed: Windows 7 - 4 GB RAM - 500 GB HDD - DVD SuperMulti - 15.6" HD anti-g