This essay tries to answer questions related to banks and their impact on the economy. The purpose of this study is to point out the function and regulation of the banks, and the impact of monetary and fiscal policy on economic stability. The aim of bank regulation is to protect the banking system and mitigate the consequences of banking crises. The central bank is the main determinant of every financial system, which in various ways strives to maintain price stability. For this reason, we will present the bank as a part of the financial system to understand its importance. We will present a selection of several growth models that have been developed through the history, and which have been influenced by various economists. The economic experts' starting points differed, although the majority agreed on the fundamental and most important goals, which were stable prices and sustainable development.