These two words are used interchangeably. Please don’t. They mean different things. Here is my concise explanation.

Argument

A value passed into a function/method during invocation.

my_func(arg1, arg2)

Additional names for “argument” are “actual argument” and “actual parameter”.

Parameter

A name of a variable in the function/method definition. During invocation, the variable is used in the function/method body to refer to the value of the passed argument.

F my_func(param1, param2) {
  ...
  # Using param1 and param2 for a computation
  ...
}

Additional name for “parameter” is “formal argument”.

Tip – Parametrize

If you struggle to remember which one is which, this might help: when you “parameterize” a piece of code, you add parameters to the code. Then you have the code with the parameter used in it, with the first occurrence in the function/method definition.

# Initial version

echo("Hello, Joe")

# Parametrized version. "name" is a parameter.

F hello(name) {
  echo("Hello, ${name}")
}

See Also

• https://en.wikipedia.org/wiki/Parameter_(computer_programming)
• https://developer.mozilla.org/en-US/docs/Glossary/Argument
• https://developer.mozilla.org/en-US/docs/Glossary/Parameter
• https://stackoverflow.com/questions/156767/whats-the-difference-between-an-argument-and-a-parameter

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Hope this helps! Have a nice day!

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Updates after Reddit discussion:

• I never asked the difference as an interview question. If I would:
  • Getting this wrong – tiny negative point
  • Not understanding why using correct terminology matters – big negative point
  • Understanding the difference and using these words interchangeably (knowingly incorrectly) – huge negative point
  • Providing fake facts to support your opinion that these words are interchangeable – huge negative point
• Explaining why using correct terminology matters is out of scope of this post