Recursive function helps to solve the certain problems quite easily. i). What is meant by “Recursive Function”? ii). How it differs from “Iteration”?

i). A recursive function is a function that solves a problem by solving smaller instances of the same problem. Such functions make use of the fact that the solution to the overall problem depends in part on solutions to smaller instances of the same problem. In other words, a recursive function is a function that calls itself during its execution.

ii). The main difference between recursion and iteration is that recursion is a process, always applied to a function and iteration is applied to the set of instructions which we want to get repeatedly executed. In recursion, the function call itself until the base condition is reached. In iteration, a sequence of instructions is repeated until the condition is met.

In terms of efficiency, iteration is generally considered better than recursion. Recursion uses more memory because it needs to store the state of all recursive calls, while iteration doesn't need to do this. However, recursion can make the code cleaner and easier to understand in some cases.