Stack
A stack is a linear data structure that follows the Last-In-First-Out (LIFO) principle, where elements are added and removed from the same end called the 'top'. It supports two primary operations: push (to add an element) and pop (to remove the top element), often with additional operations like peek (to view the top element) and isEmpty (to check if empty). Stacks are fundamental in computer science for managing function calls, expression evaluation, and undo mechanisms in applications.
Developers should learn stacks for implementing algorithms that require LIFO order, such as parsing expressions (e.g., in compilers), managing browser history (undo/redo features), and handling recursive function calls (via call stacks). They are essential in system-level programming, like memory management and backtracking problems, and are widely used in interview questions for data structure proficiency.