This book is devoted to the reforms of the public finance sector both in the structure of public expenditure and revenues, as well as in the management of public finances in the context of planned comprehensive reforms in Poland. In public finances, as in any other field, there are misunderstandings and false judgments resulting from the inadequate knowledge of the conditions underlying the phenomena and financial processes. Understanding the basics of public finances requires systematizing knowledge about basic issues. Starting from this assumption, the author attempts to explain the complexity of public finance issues. The book is to be used as an aid in learning and mastering the basics of public finances. It consists of two parts. The first part first defines the basic concepts of financial theory, including public finances, characterized the public finance sector and public finances in the EU, discussed, among others: - the problem of money, - the impact of exchange rate policy on currency convertibility, - the structure of income and public expenditure, - internal audit in the public finance sector and internal financial control, - the budget deficit and the state budget.