• Recursive function: a function that calls itself
• Must contain a termination condition, or base case
• Also contains the recursive call to itself with modified input

0 | def my_recursive_function(input_value):
1 |     # base case
2 |     if base_case_condition:
3 |        return base_case_output_value
4 |     # recursive call
5 |     else:
6 |        return my_recursive_function(modified_input_value) + some_modification