What is the main role of a stack in programming and what is it used for?

A stack is a data structure that operates on the Last In, First Out (LIFO) principle, meaning the last added element is retrieved first.

In programming, a stack is used for:

• Storing call context of functions (call stack). When a function is called, its parameters and local variables are placed on the stack, and after completion, they are removed.
• Managing return from functions, saving return addresses.
• Implementing algorithms that require reverse processing order (e.g., graph traversal, parsing).

Example: when calling function A, which calls function B, the context of A is placed on the stack, then B. After B finishes, control returns to A, and the context of B is removed from the stack.