Supercomputers are typically so expensive that computing time using them is a precious resource, even if the machines are available 24-7. For publically funded machines, supercomputing time is allocated through a peer-review process, when a team of scientists and specialists assess the quality and potential impact of the research, and award time accordingly..
However, many web services you might use could involve HPC in some way, in the form of the large data centres that store the data for your social presence on the web. HPC and supercomputers will undoubtedly touch your life – whether that’s down to you checking the weather, investing your savings with a bank to gain interest, or going for medical tests, many fields are using HPC more and more to perform simulations and analyse data.
Of course, if you really want to get to use HPCs directly, it helps to get a background in science, computer coding and maths!