RDBMS stands for Relational Database Management System. It is a type of database management system that organizes data into tables, with each table having a unique key.

The purpose of primary keys in a relational database is to uniquely identify each record in a table. They ensure data integrity by preventing duplicate records and are used as references in other tables.

Interfaces in OOP provide a way to define a contract that classes must adhere to, promoting flexibility by allowing different classes to implement the same interface in their own way. This promotes modularity as it enables interchangeable components and reduces code dependencies.

HTTPS uses data encryption to secure the communication between the client and server, while HTTP does not provide this level of encryption. Data encryption ensures that the data exchanged between the client and server is encoded, making it difficult for unauthorized users to intercept and understand the information being transmitted. This encryption is particularly crucial for sensitive data such as login credentials, payment information, and personal details.

Arrays are statically allocated, meaning their size is fixed at compile time. In contrast, linked lists use dynamic allocation, allowing them to grow or shrink as needed during runtime. Static allocation is primarily used in arrays, where memory is allocated on the stack or heap, while dynamic allocation is more common in linked lists, providing flexibility in memory management.

A spanning tree is a subset of the edges of a graph that connects all vertices without any cycles. A minimum spanning tree is specifically the smallest such spanning tree, where the sum of the weights of its edges is minimized. Dijkstra's and Kruskal's algorithms are not specific to defining such subsets in a graph.

Static analysis tools analyze code without executing it, focusing on identifying potential issues, bugs, or violations of coding standards based on code structure, syntax, and patterns. These tools can flag issues such as unused variables, potential memory leaks, or violations of coding conventions like indentation, naming conventions, or code complexity thresholds. They are valuable in ensuring code quality, improving maintainability, and reducing the risk of introducing bugs or vulnerabilities during development. Profiling tools, on the other hand, focus on runtime behavior and performance metrics, coverage tools assess test coverage, and code review involves manual or automated inspection of code by peers or tools.

Dynamic testing involves executing the software to find defects or bugs. It includes techniques like unit testing, integration testing, system testing, and acceptance testing, where the software is actively run to check its behavior and functionality. This type of testing is essential for identifying issues that may arise during actual usage of the software.

Using WebSocket allows real-time communication between clients and the server, making it ideal for notifying users when someone is typing. setTimeout and clearTimeout are more suitable for handling delays and timeouts, not real-time updates. AJAX polling introduces unnecessary overhead and delays. The oninput event listener is used for detecting input changes, not real-time status updates.

Merge sort is a classic example of a divide and conquer algorithm, where the sorting process involves dividing the array into smaller subarrays, sorting them individually, and then merging them back together in sorted order.