Cloud - Cloud computing is the on demand availability of computing resources, with a focus on data storage and processing capacity, without direct management by the user in wikipedia

HPC - High Performance Computing refers to the use of supercomputers with computing nodes running in parallel connected by a high-speed, low latency network to complete tasks that require large amounts of resources in wikipedia

HTC - High Throughput Computing or Distributed Computing refers to the use of geographically distributed computing resources over long periods of time in wikipedia

PRACE - The Partnership for Advanced Computing in Europe is a non-profit European association that brings together several members and supercomputers in Europe, allowing the shared use of these resources for scientific research and technological innovation Website

Supercomputer - is a computer with a high level of performance compared to a common computer. These supercomputers are often called HPC clusters in wikipedia