This chapter introduces the key building blocks of the electricity market in Europe. From the First Energy Package in 1996 to the Fifth Energy Package in 2021, Europe’s single, integrated electricity market has been evolving over the last three decades. The Guideline on Capacity Allocation and Congestion Management (CACM Guideline) is also introduced, which ensured that market coupling became the mandatory means of allocating cross-zonal capacity in the day-ahead and intraday timeframes. Furthermore, this chapter describes the key aspects of the integrated market design from bidding zones and market coupling to price formation and congestion income. Additionally, the enablers of market coupling including Transmission System Operators, Regional Coordination Centres, and Nominated Electricity Market Operators are explained. The chapter closes by discussing current and upcoming developments in market coupling.