Greetings, coder!

Today, we're unraveling the world of recursion. Recursion is a scenario in which a function calls itself. Think of Russian Matryoshka dolls -- each doll contains a smaller doll inside, which mirrors the concept of recursion.

Recursion is valuable when you can break down a problem into smaller, yet similar, simpler problems. It plays a critical role in various tasks such as sorting and searching algorithms.

The lesson for today involves understanding recursion, implementing it in C++, comparing it with iteration, and practicing debugging it.

Recursion in programming occurs when a function solves a problem by resolving smaller instances of the same problem. This is akin to tracing a family tree -- each person reports their parent, who, in turn, does the same. This process of lineage tracing serves as a good metaphor for recursion.

However, it is paramount to define a proper base case in recursion to bring it to an end and avoid infinite loops.

Now, we will examine recursion in C++ using factorials as an example. The factorial of n is n times the factorial of n-1.

Here is the C++ implementation: