What is parenthesis?

Good question!

In programming, parentheses (the rounded brackets ()) are used in different ways depending on the context.

Here are two common uses:

• Grouping expressions to control the order of operations:
  Example:

  (5 + 19) / 6 * (2 + 5) 

  Parentheses make sure that the additions happen before division and multiplication.
  

• Defining function calls and passing arguments:
  Example:

  // function definition
  int main() {
     ...
  }
  
  // Function call
  addNumbers(10, 5); 

  Here, parentheses are used to define and call functions, and to pass values into them.

You'll be using parentheses a lot as you continue learning to code, and it will start feeling more natural as you progress.
So I suggest you keep moving forward step-by-step.

Let me know if you have any more questions—happy to help!