A graphing calculator is a handheld device designed to plot graphs, solve equations, and perform complex calculations. It features a large display that can show multiple lines of data and graphs simultaneously, making it useful for students and professionals in fields like mathematics, engineering, and science. These calculators can handle various functions, including algebraic equations, calculus, and statistics. Many models also allow users to program custom functions and store data, enhancing their versatility. Popular brands include Texas Instruments, Casio, and HP, each offering different features to cater to user needs.