HPC

A computer simulation is, as Wiki puts it, an imitation of the operation of a real-world process or system over time. For my case, I need to solve mathematical equations applied to the Universe or to Galaxies, repeatidly and accurately. Thus, I utilize computers and their specialized softwares in order to do calculations that a human brain cannot afford. 

Universities and Research Institutes have clusters of computers to do their analytical work. These are powerful machines, more powerful than a normal laptop, capable of doing more complicated tasks, faster and more detailed computations.

High-performance computing (HPC) is running jobs on parallel, using hundreds or thousand of computer cores, while for example my MacBook Pro has 7 physical cores. 

I have been using chimera cluster for my computations. This is the cluster of computers at the Astronomical Institute of Charles University, in Troja, Prague, Czech Republic. FYI, slurm is its operating queue system.