I am an absolute beginner when it comes to the Arduino board, and reading other peoples code, made no sense to me, simply because I did not know what the code meant.
In my search for knowledge, I came across a series of YouTube tutorials that has at least thrown some light on the subject, for me.
If you are struggling as I am, I suggest you have a look at these well constructed, professional tutorials.
They run from series 1 to series 12
Ken