There are a lot of things in the world whose functioning and appearance were determined even before they are perceived or before they occur.
It is already determined in a nut or seed what the tree or the flower will look like.
Genetic information of living beings is determined by a defined sequence, a code. This code forms a kind of alphabet of life, and life follows this established code.
Robots, too, follow an established code. The way a robot moves has been determined beforehand by a series of commands. The robot only performs what was written down before via rules and signs in a specially coded language. The code guides the robot.
So coding or programming means, simplified, that in a first step a language is agreed upon with signs and rules with which then, in a second step, codes can be determined that are understood and executed.