I find there are 2 kinds of parameters as shown below:

• The required parameter like p1 which must get an argument from a function call because it doesn't have a default value.
• The optional parameter like p2, *args or **kwargs which optionally gets an argument from a function call because it has a default value.

def func(p1, p2='World'):
    print(p1, p2)

func(p1='Hello')
# Hello World

def func(*args, **kwargs):
    print(args, kwargs)

func()
# () {}

So, the glossary of parameter should also explain required parameter and optional parameter in addition to the 5 parameters as shown below:

... There are seven kinds of parameter:

• positional-or-keyword: ...
• positional-only: ...
• keyword-only: ...
• var-positional: ...
• var-keyword: ...
• required: ...
• optional: ...