An industrial robot arm without a program is an expensive, inert piece of hardware. Everything that makes it useful — the sequence of pick points, the weld path, the exact moment a gripper closes — comes from the program loaded into its controller, and that program is almost always built using the same core set of concepts regardless of which manufacturer built the robot. FANUC, ABB, KUKA, and Yaskawa each ship a different programming language with its own syntax and menu structure — TP, RAPID, KRL, and INFORM respectively — which can make robot programming look like it needs to be relearned from scratch for every vendor. It doesn't. Underneath the differing keywords, every industrial robot programming environment expresses the same handful of ideas: teaching physical points, choosing how the robot moves between them, reading and reacting to inputs and outputs, organizing logic into reusable subroutines, and controlling speed and acceleration. Learn those concepts once, generically, and picking up any specific vendor's syntax becomes a matter of days, not a fresh start.
The Teach Pendant: How Robots Are Actually Taught
The teach pendant is the handheld controller — a screen, a set of jog buttons or a joystick, and physical hardware safety controls including an emergency stop and a deadman's switch — that an operator or programmer uses to directly control and program the robot up close. Before a robot can execute any automated program, most of its motion points originate from an operator physically jogging the arm, axis by axis or in a chosen coordinate frame, to the exact physical position needed and recording that position into the program. This process, called teaching, is why teach-pendant programming is sometimes described as programming by demonstration: rather than typing exact X-Y-Z-orientation coordinates from a drawing, the programmer moves the real (or simulated) robot to the real location and tells the controller "remember this point."