LIBOR is the average interest rate at which a select group of banks can borrow money from one another. It is used as a benchmark for short-term interest rates worldwide, and is used to set rates on hundreds of trillions of dollars of financial contracts, including mortgages, credit cards, and student loans.

The scandal came to light when it was revealed that several banks had been submitting false information about the rates at which they could borrow money in order to influence the overall LIBOR rate. This allowed the banks to profit from trades and to appear financially stronger than they actually were. The manipulation of LIBOR was accomplished by traders at multiple banks who submitted false information to the British Bankers' Association (BBA), which was responsible for calculating the rate.

The banks involved in the scandal included Barclays, Royal Bank of Scotland, UBS, and Deutsche Bank, among others. As a result of the scandal, several banks were fined billions of dollars by financial regulatory bodies, and several traders and executives were charged with criminal offenses. The scandal also led to the resignation of several high-profile executives, including the CEO of Barclays.

The LIBOR scandal had far-reaching consequences, as it undermined the integrity of financial markets, reduced trust in the banking system, and led to significant legal and financial penalties for the banks involved. It also led to significant reforms in the way that benchmark interest rates are calculated and regulated, to prevent similar scandals from happening in the future.