The introductory part of this bachelor thesis describes the importance of supercomputers and computers in today's society, but also through history. The reasons for choosing this topic are also listed. The structure of modern supercomputers - their size, strength, number of processors and cores, used operating systems – is presented in the main part. Some of the advantages of supercomputers and their limitations and performance problems are also described. Furthermore, the purpose and use of supercomputers nowadays is shown. Moreover, the list of the top 500 supercomputers is presented (www.top500.org). The strongest supercomputers of the world are briefly presented and the distribution of supercomputers by country and continents, architecture, applications and so on is presented with graphs. I also mentioned Blue Waters which is currently the most powerful supercomputer which is not on the list of the top 500 supercomputers. The reasons why the Blue Waters is not listed are described. Croatian supercomputers are presented after that - how many are there, where they are, for what are they used, what are their hardware features. At the end, I presented two projects from around the world which use supercomputers and described what role supercomputers could have in the future, what are the expectations for further development and innovation in this area.