Linked Lists:

Linked lists are a type of data structure that consists of a sequence of nodes, where each node contains a data element and a reference (or pointer) to the next node in the sequence. Unlike arrays, linked lists do not require contiguous memory allocation, allowing for efficient insertion and deletion at any position.

Key Points:

- Singly Linked List: In a singly linked list, each node has a reference to the next node in the sequence. The last node points to null, indicating the end of the list.
- Doubly Linked List: In a doubly linked list, each node has references to both the previous and next nodes in the sequence, enabling traversal in both directions.
- Circular Linked List: In a circular linked list, the last node points to the first node, creating a circular structure.

Operations on Linked Lists:

- Traversal: Linked lists can be traversed sequentially by starting from the head node and following the next pointers until reaching the end of the list.
- Insertion: Nodes can be inserted at the beginning, end, or any position within a linked list by adjusting the next pointers of the surrounding nodes accordingly.
- Deletion: Nodes can be removed from a linked list by updating the next pointers of the surrounding nodes to bypass the node to be deleted.
- Searching: Linked lists can be searched for a specific value by traversing the list and comparing each node's data element with the target value.

Stacks:

A stack is a linear data structure that follows the Last-In-First-Out (LIFO) principle, where the element that is inserted last is the first one to be removed. Stacks can be implemented using arrays or linked lists.

Key Points:

- Push: Adding an element to the top of the stack is known as pushing.
- Pop: Removing the topmost element from the stack is known as popping.
- Top: The top of the stack refers to the element that would be popped next.
- Empty: A stack is said to be empty when it contains no elements.
- Full: A stack is said to be full when it reaches its maximum capacity.

Operations on Stacks:

- Push: Adds an element to the top of the stack, increasing its size.
- Pop: Removes the topmost element from the stack and returns it, decreasing its size.
- Peek: Returns the value of the topmost element without removing it.
- isEmpty: Checks if the stack is empty.
- isFull: Checks if the stack is full (for array implementation).

Applications:

- Expression evaluation (using postfix notation).
- Function call stack management.
- Undo/redo operations in text editors.
- Backtracking algorithms.
- Browser history navigation (forward and backward).