The second set of acronyms shows that just because you think you know the answer you might not. The problem with *aaS acronyms is that companies are always making new ones up, this means that for a while there are often two definitions for the same acronyms.
DaaS : Desktop as a Service
The most common use of DaaS is Desktop as a Service. This model offers the provision of a virtual desktop to users using VDI technology. The solution is normally hosted by a third pary cloud service provider and is often charged on a monthly fee per user. VDI can be provisioned within the corporate infrastructure but this would not be DaaS. Two of the biggest providers are VMware Horizon Air and Amazon WorkSpaces
DaaS : Data as a Service
This service is a model under which data: Text, images, sound or video for example is provided by a central repository to customers regardless of their location. An example of this is Oracles Data-as-a-Service.
HPC : High Performance Computing
High Performance Computing is the use of either parallel processing or super computers to deliver a performance that is able to solve complex computational problems. HPC is used extensively within the field of research using computer modelling, simulation and analysis of often large data sets.