## Key Concepts

Review core concepts you need to learn to master this subject

### What is Recursion

Recursion is a strategy for solving problems by defining the problem in terms of itself. A recursive function consists of two basic parts: the base case and the recursive step.

Recursion: Conceptual
Lesson 1 of 1
1. 1
You’ve heard about a trendy new spot that sells fruit sandwiches. What are fruit sandwiches? You have no idea, but you’re eager to find out! Sadly, when you arrive at the store, the line is out t…
2. 2
Recursion is a strategy for solving problems by defining the problem in terms of itself. For example, to sum the elements of a list we would take the first element and add it to the **sum of t…
3. 3
A recursive approach requires the function invoking itself with different arguments. How does the computer keep track of the various arguments and different function invocations if it’s the sa…
4. 4
Recursion has two fundamental aspects: the base case and the recursive step. When using iteration, we rely on a counting variable and a boolean condition. For example, when iterating through the …

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