Using blocks for code repetition is advantageous because: 1. Makes code shorter and less cluttered and 2. Makes it easier to find problems in your code and debug.
Parameters are simply placeholders for values that are defined in your code blocks.
The Pythagorean Theorum takes parameters to calculate the hypotenuse of a right triangle.
A situation where parameters are not needed is when performing actions that are set, not with variables that need to correspond to the defined block.
This program asks for names that are to be put into an alphabetical list. It does this repeatdly getting a name, adding to the list, then uses the letters of the name to compare to the others, then puts them in a list and repeats until everything is correct.