Arguments are defined in parentheses after the function name:

def divide(dividend, divisor):  # The names of the function and its arguments
    # The arguments are available by name in the body of the function
    print(dividend / divisor)

The function name and its list of arguments are called the signature of the function. Each named argument is effectively a local variable of the function.

When calling the function, give values for the arguments by listing them in order

divide(10, 2)
# output: 5

or specify them in any order using the names from the function definition:

divide(divisor=2, dividend=10)
# output: 5