What's the difference between an argument and a parameter?

A parameter is a variable in a method definition. When a method is called, the arguments are the data you pass into the method's parameters.

public void MyMethod(string myParam) { }

...

string myArg1 = "this is my argument";
myClass.MyMethod(myArg1);

Parameter is variable in the declaration of function.

Argument is the actual value of this variable that gets passed to function.

Simple:

• PARAMETER → PLACEHOLDER (This means a placeholder belongs to the function naming and be used in the function body)
• ARGUMENT → ACTUAL VALUE (This means an actual value which is passed by the function calling)