A casino is a place where gambling activities take place. Some of these facilities add a wide range of luxuries to the mix in order to attract players, but even less fancy places that specialize in games of chance can be called casinos.
There are a number of different types of gambling activities that can be done in casinos, from blackjack to roulette to craps. Slot machines are the most popular, and are the ones that bring in a large percentage of the profits for casinos. These machines work by allowing the player to insert money and then watch bands of colored shapes roll past on reels (either actual physical reels or a video representation of them). When a specific pattern appears, the machine pays out a predetermined amount of money.
Something about the act of gambling seems to inspire people to cheat, steal and scam their way into a jackpot, which is why casinos spend a lot of time, effort and money on security. In addition to the obvious security measures (cameras in every room, a dedicated area for table games, strict dress codes and so on), casinos also use technology to monitor the games themselves. For instance, in chip tracking systems, betting chips have built-in microcircuitry that allows the casinos to supervise them minute by minute and immediately notice any statistical deviation from expected results.
Some casinos also reward their “good” players with free food, hotel rooms, tickets to shows and so on. These are referred to as comps. These are often given to people who play long sessions at the tables or spend a large amount of time on slot machines.