A graphing calculator is a handheld computer that is capable of plotting graphs, solving simultaneous equations, and performing other tasks with variables. Most popular graphing calculators are programmable calculators, allowing the user to create customized programs, typically for scientific, engineering or education applications. They have large screens that display several lines of text and calculations.

A mobile device or handheld computer is a computer small enough to hold and operate in the hand. Mobile devices are typically battery-powered and possess a flat-panel display and one or more built-in input devices, such as a touchscreen or keypad. Modern mobile devices often place emphasis on wireless networking, to both the Internet and to other devices in their vicinity, such as headsets or in-car entertainment systems, via Wi-Fi, Bluetooth, cellular networks, or near-field communication.