How do you define a function in Python? Do we need to use the def word when we "call" or "use" the function?

How many arguments/parameters can we send to a function when we call it? Do we have to give the exact number of arguments, and what is the star "*" used for in the place of the arguments when we define a function?

Inside our function code (the indented part) what does the "return" do, and do we need to have always a return or not? Does the return always have to be as the very last statement of the function and why?

How do we capture what the return statement sends when we call the function?

The (new) Named variables we create inside the function are they available to be accessed outside the function?

If a variable is created before and outside the function, can it be accessed/changed inside the function?