RAM (Random Access Memory) is volatile memory used for temporary storage during program execution. It is faster but loses its data when power is turned off. ROM (Read-Only Memory) is non-volatile memory used to store firmware and is not erased when power is turned off.
What is the purpose of an operating system?
An operating system manages hardware and software resources of a computer system, providing services for executing programs, managing memory, handling input/output operations, and ensuring system security.
Describe the difference between TCP and UDP protocols.
TCP (Transmission Control Protocol) provides reliable, connection-oriented communication by ensuring data delivery and error checking. UDP (User Datagram Protocol) is connectionless and provides unreliable, but fast communication, suitable for real-time applications like video streaming.
What is the difference between a compiler and an interpreter?
A compiler translates entire source code into machine code before execution, generating an executable file. An interpreter translates code line-by-line during execution without generating an intermediate file.
Explain the concept of virtual memory.
Virtual memory is a memory management technique that uses disk space as an extension of RAM. It allows running processes to use more memory than physically available by swapping data between RAM and disk.
What is object-oriented programming (OOP)? Give an example.
Object-oriented programming is a programming paradigm based on the concept of objects, which can contain data in the form of attributes and code in the form of methods. Example: Creating a "Car" class with attributes like make, model, and methods like start() and stop().
Describe the difference between abstraction and encapsulation in OOP.
Abstraction is the process of hiding irrelevant details and showing only essential features of an object. Encapsulation is the bundling of data and methods that operate on the data into a single unit, protecting data from outside interference and misuse.
What is polymorphism and how is it implemented in programming languages?
Polymorphism allows objects of different types to be treated as objects of a common superclass. It is implemented through method overriding and method overloading in programming languages.
Explain the concept of inheritance in object-oriented programming.
Inheritance is a mechanism where a new class inherits properties and behaviors (methods) of an existing class. It promotes code reusability and establishes a relationship between classes, such as parent-child.
What are the different types of sorting algorithms? Explain one of them.
Sorting algorithms include Bubble Sort, Insertion Sort, Selection Sort, Merge Sort, Quick Sort, etc. Example: Merge Sort divides the array into two halves, recursively sorts each half, and then merges them back together in sorted order
What is a linked list? How is it different from an array?
A linked list is a linear data structure where elements are stored in nodes, each containing a value and a pointer/reference to the next node. Unlike arrays, linked lists do not have a fixed size, and memory allocation is dynamic. Insertions and deletions are faster in linked lists compared to arrays, but accessing elements by index is slower.
Explain the concept of dynamic programming.
Dynamic programming is a technique used to solve problems by breaking them down into smaller overlapping subproblems and solving each subproblem only once. The results of subproblems are stored in a table to avoid redundant computations, improving efficiency.
What is a database index? Why is it important?
A database index is a data structure used to improve the speed of data retrieval operations on a database table by providing quick access to rows based on the values of certain columns. It is important because it reduces the number of disk I/O operations required to fetch data, thus improving query performance.
What is normalization in database management?
Normalization is the process of organizing data in a database efficiently by eliminating redundancy and dependency. It involves breaking down a table into smaller, well-structured tables and defining relationships between them to minimize data duplication and improve data integrity.
Explain the difference between a primary key and a foreign key.
A primary key is a unique identifier for each record in a database table and ensures data integrity and entity identification. A foreign key is a column or combination of columns in one table that references the primary key in another table, establishing a relationship between the two tables.
What is a join in SQL? Explain different types of joins.
A join in SQL is used to combine rows from two or more tables based on a related column between them. Different types of joins include INNER JOIN (returns rows when there is a match in both tables), LEFT JOIN (returns all rows from the left table and matching rows from the right table), RIGHT JOIN (returns all rows from the right table and matching rows from the left table), and FULL OUTER JOIN (returns all rows when there is a match in either table).
Describe the concept of multithreading and its advantages.
Multithreading is the ability of a CPU to execute multiple threads concurrently within a single process. Advantages include improved responsiveness, better resource utilization, and simplified program design for tasks that can be parallelized.
What is the purpose of a firewall in networking?
A firewall is a network security device or software that monitors and controls incoming and outgoing network traffic based on predetermined security rules. Its purpose is to protect a network from unauthorized access, data breaches, and malware attacks.
Explain the OSI model and its different layers.
The OSI (Open Systems Interconnection) model is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven abstraction layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application. Each layer has specific functions and interacts with adjacent layers to facilitate communication between devices.
What are the different types of network topologies?
Network topologies include Bus, Star, Ring, Mesh, and Hybrid. Bus topology uses a single communication line, Star topology connects all devices to a central hub, Ring topology connects each device to two other devices forming a closed loop, Mesh topology connects each device to every other device directly, and Hybrid topology combines two or more topologies.
