Answer:
Stack
Explanation:
Any function that call itself can be regarded as recursive function, it should be noted that Recursion is a natural use for a stack, especially in the area of book keeping.
Recursion is very important because some of problems are usually recursive in nature such as Graph and others, and when dealing with recursion , only base and recursive case is needed to be defined.
Some areas where recursion is used are in sorting and searching.