1. Initialize an ArrayList to store all the permutations.
2. Check for the base conditions i.e. if the input is null, return the input itself. If the input is a single Character or an empty String, add it to the list.
3. Separate out the first character and recursively find the permutation of the remainder String.
4. Iterate and insert the separated character at every position in all the words obtained from the recursive call.
5. Return the list of all the words.
