What is iterable,/,* ,keyin sorted function

#1

i want to ask that key paramter is used to sort tht returend values by key or to sort the iterable on the basis of returned values by key??

and what are /,* after iterable

#2

In sorted function iterable is a list or an array that is to be iterated and sorted .The key just defines on the basis of which the iterable needs to be sorted like if there is multiple columns like name,id and rollno and you want to sort the iterable according to the rollno you will need to write a function that returns rollno of the list and then assign that function to parameter key of sorted function which will allow sorted function to sort the list according to rollno.
You can look at the examples here to gain more insight:

#3

iterable The sequence to sort, list, dictionary, tuple etc. on which sorting is being performed

keyis Optional. A Function to execute to decide the order. Default is None. can be length as deciding factor by putting key=len