This book provides the foundational knowledge essential for comprehending the functioning of financial markets and institutions and their current challenges. First, the book provides a general overview on the functioning of the EU financial system, examining financial markets and financial intermediaries' features and activity and their contribution to economic growth. It also outlines the evolution of the EU integration process, giving an overview of the most important regulatory steps related to the banking and financial system culminated in the creation of the Banking Union. Banking activity is also examined in the most important business areas: commercial versus investment banking. Lastly, the book introduces two important phenomena, which are currently characterizing the financial environment: FinTech and sustainable finance. Both FinTech and sustainable finance represent significant opportunities for the market and the operators, even if the challenges and risks associated are also relevant. This underlines the need to understand their intensity and their potential impact on the functioning of the financial system as a whole.