Keyestudio KS0436 Kit Manual page 24

delay(1000); // wait for a second.
digitalWrite(ledPin, LOW); // set the LED off.
delay(1000); // wait for a second
}
 Single line comments start with
Code Explanation:
of that line is considered a comment.
Comments are a great way to leave notes in your code explaining
why you wrote it the way you did.
 The first line of code is:
int ledPin = 10; // define digital pin 10
As the comment above it explains, this is giving a name to the pin that
the LED is connected to. You can change the connection pin here.
 Next, we have the "setup" and "loop" function
void setup()
Every Arduino sketch must have a 'setup' function, and the place where
you might want to add instructions of your own is between the { and
the }.
In this case, there is just one command there, which, as the comment
// and everything up until the end
24