The Great Recession was a severe economic downturn that began in late 2007 and lasted until mid-2009. It was triggered by a collapse in the housing market, where many people had taken out risky loans to buy homes they couldn't afford. When housing prices fell, millions of homeowners found themselves owing more than their homes were worth, leading to widespread foreclosures and financial instability. This crisis affected not just the United States but economies around the world. Major financial institutions, like Lehman Brothers, faced bankruptcy, and governments had to step in to stabilize the economy. The recession resulted in high unemployment rates and significant changes in financial regulations to prevent a similar crisis in the future.