PYQ Bank — Bank PO / Clerk

IaaS (Infrastructure as a Service) provides virtualized computing resources like servers, storage, and networking over the internet, requiring organizations to manage applications, data, and middleware.

PaaS (Platform as a Service) abstracts the infrastructure layer and provides a ready-made development and deployment environment with pre-configured middleware, databases, and development tools, shifting more infrastructure management responsibility to the provider.

The key distinction is the level of abstraction and management responsibility; PaaS handles more backend infrastructure, allowing developers to focus purely on application development.

Option A incorrectly describes IaaS as storage-only, option C confuses cost with features, and option D ignores the substantial architectural differences between these service models.

A stack overflow occurs when a program attempts to use more memory on the call stack than is available, typically caused by infinite recursion, excessive recursion depth, or deeply nested function calls.

The call stack has a limited size, and each function call adds a frame to it; when this limit is exceeded, a stack overflow error occurs.

The best prevention is to identify recursive patterns and replace them with iterative solutions, use tail recursion (which some compilers optimize), or implement safeguards like recursion depth limits.

Option A incorrectly attributes this to RAM insufficiency, option B confuses heap with stack memory, and option D overlooks that global variables are stored in the data segment, not the call stack.

Symmetric encryption uses a single shared key for both encryption and decryption, making it fast but requiring secure key exchange beforehand.

Asymmetric encryption uses a public-private key pair, eliminating the need to securely transmit keys beforehand, making it ideal for secure initial communication and digital signatures.

Although asymmetric encryption is computationally expensive, it is preferred in scenarios like SSL/TLS handshakes, email encryption, and digital signatures where secure key distribution is essential.

In practice, hybrid approaches combine both methods for optimal security and performance.