What is the main difference between recursion and iteration?

The main difference between recursion and iteration lies in how they repeat a set of instructions:

1. Recursion:

   • A function calls itself to solve a smaller instance of the same problem.
   • It typically involves a base case to terminate the recursive calls.
   • Each call adds a new layer to the call stack, which can lead to higher memory usage.

2. Iteration:

   • A loop (such as for or while) repeatedly executes a block of code until a specified condition is met.
   • It does not involve function calls and uses a single stack frame, which generally results in lower memory usage.
   • Iteration is often more efficient in terms of performance compared to recursion for problems that can be solved with loops.

In summary, recursion uses function calls to repeat actions, while iteration uses loops.