The TI-84 is a graphing calculator produced by Texas Instruments. It was introduced in the year 2004 and features a full-color display, a rechargeable battery, and a backlit screen for improved visibility in low-light environments. The calculator has a large library of pre-installed applications, including graphing, statistics, and mathematical functions. The TI-84 is widely used in schools and universities around the world, as well as in professional settings in engineering, science, and business. It is considered to be one of the most popular and durable graphing calculators on the market.