Sequencing can provide genomic characterisation of a specific organism, as well as of a whole environmental or clinical sample. High Throughput Sequencing (HTS) makes it possible to generate an enormous amount of genomic data at gradually decreasing costs and almost in real-time. HTS is used, among others, in medicine, veterinary medicine, microbiology, virology and epidemiology. The paper presents practical aspects of the HTS technology. It describes generations of sequencing, which vary in throughput, read length, accuracy and costs ̶ and thus are used for different applications. The stages of HTS, as well as their purposes and pitfalls, are presented: extraction of the genetic material, library preparation, sequencing and data processing. For success of the whole process, all stages need to follow strict quality control measurements. Choosing the right sequencing platform, proper sample and library preparation procedures, as well as adequate bioinformatic tools are crucial for high quality results.