Parameters are variables that are used to store the data that's passed into a function for the function to use.

On the other hand, Arguments are the actual data (values) that's passed into a function when it is invoked.

example: Are x and y "parameters" or "arguments" in the below function?

function findAverage(x,y) {
  let avg = (x + y) / 2;
  return avg;
}

console.log(findAverage(11, 7));

Answer:

x and y are parameters! They are defined in the function declaration. The values 11, and 7 are passed in as function arguments.

Credits: Udacity