Answer:
A data structure if I'm correct.
Step-by-step explanation:
The computer would need to know when one command is over, as you can write code like this,
ellipse(20, 20, 20, 20);fill(255, 0, 240);
and without the semicolon it would end up looking like this,
ellipse(20, 20, 20, 20)fill(255, 0, 240)
and the computer would not know when you've stopped creating the circle and when you've started to color it.