Our course on the basics of thermodynamics targeting a wide audience includes only what is absolutely necessary, focusing on the most basic issues, excluding less important specialized topics. However, you will learn about unusual phenomena such as stretched liquid and see interesting experiments. A future competent specialist, whose work should be at least somehow connected with physical phenomena, will find this course in thermodynamics useful and necessary. We tried to explain the basic concepts as clearly and consistently as possible and at the same time remain at a serious physical level. As a result, in a relatively short time, you will receive a core of knowledge that will allow you to easily supplement it with appropriate special tasks in the future. In addition, such an ultra-short extract of the essentials often allows you to look at the course differently: to cover it as a whole, to see the interconnection of the parts. So, it may be of interest even to those who have already studied thermodynamics.