A casino is a place where people can play games of chance for money. It usually also includes restaurants, bars, and stage shows. It is the most popular form of gambling in many countries.
Modern casinos use a lot of technology to monitor their operations. Video cameras monitor the gaming areas to watch for suspicious activity, and computer systems supervise the games themselves. For example, betting chips with built-in microcircuitry allow casinos to monitor the exact amounts wagered minute by minute and alert them if there is any deviation from expected results; roulette wheels are electronically monitored to discover any statistical variation from normal operation. These sophisticated systems require skilled mathematicians and computer programmers to operate.
In addition to these technologies, casinos employ a large staff of security personnel. They are usually divided into a physical security force and a specialized surveillance department, the latter operating closed-circuit television (known as the eye in the sky) and monitoring for suspicious or definite criminal activity. Casinos also have a number of other security measures, including a sophisticated security network and a system of armed guards who patrol the premises.
Although the precise origin of gambling is unknown, it is widely believed that it has been a part of human society for millennia in one form or another. The oldest evidence dates from 2300 BC China, when archaeologists discovered a game of chance using wooden blocks; dice came into use around 500 BC in Rome, and card games were introduced in the early 1600s. Various games of chance are featured in paintings of the period, such as Cardsharps by Caravaggio and The Triumph of Death by Pieter Bruegel the Elder.