High Performance Computing generally uses large arrays of computers connected in clusters or grids.
HPC systems usually come in 3 varieties:
- Cluster computers, sometimes called Beowulf clusters are generally built out of a number of regular computers in order to get the throughput of supercomputers.
- Grid computers, are also generally built out of a number of regular computers.
The main difference between Grids and Clusters have to do with the communication between computing nodes (a node will be a CPU core). If there will be a lot of communication, one generally calls it a cluster. In contrast, Grids tend to have little communication between nodes.