A parameter is a special kind of variable used in a function to refer to one of the pieces of data provided as input to the function. These pieces of data are the values of the arguments with which the function is going to be called/invoked.

Argument: An argument is referred to the values that are passed within a function when the function is called. These values are generally the source of the function that require the arguments during the process of execution. These values are assigned to the variables in the definition of the function that is called. The type of the values passed in the function is the same as that of the variables defined in the function definition. These are also called Actual arguments or Actual Parameters.

Parameter: The parameter is referred to as the variables that are defined during a function declaration or definition. These variables are used to receive the arguments that are passed during a function call. These parameters within the function prototype are used during the execution of the function for which it is defined. These are also called Formal arguments or Formal Parameters.