A stack is a fundamental data structure in programming that follows the Last-In-First-Out (LIFO) principle. It allows operations like push (adding an element) and pop (removing the top element). Understanding stacks is essential for mastering programming fundamentals.

Generally, two step interview process. First interview by HR and 2nd interview is technical. HR screen the suitable candidate for Job regarding qualification and experience base and technical interview is given by manager of concern department.