Lets open up one of the programs that come with the Arduino software and make a few changes to it.
Lets look at this blink program and we will change the time delay a little bit so that the blinking can go faster or slower.
Now the Arduino comes with hundreds or more prewritten libraries and special functions that interact with the Arduino hardware board.
Here are some of these prewritten functions:
You will notice the brackets and some strange words like Void and setup and words in brackets in CAPITAL LETTERS.
Here is a good Youtube/Instructable site showing the programming of a basic robot arm. It is by the user MjRoval https://www.instructables.com/Programmed-Robot-Arm/