An argument in computer programming refers to any piece of data that is passed into a module when the module is called. This data is known as an argument or input. It is used to provide information to the module and can be used to perform specific actions or calculations.
Parameter variables, also known as parameters, are special variables that receive arguments when a module is called. They act as placeholders for the values that will be passed into the module. The parameter variables allow the module to work with different values without needing to modify the module itself.
For example, consider a function that calculates the area of a rectangle. The function may have two parameter variables: length and width. When the function is called, argument values for length and width can be provided, such as 5 and 10. These argument values are then assigned to the parameter variables, allowing the function to calculate the area using the provided values.