WAEC Computer Science 2022
Questions & Answers

A hypervisor, also known as a virtual machine monitor (VMM), is software, firmware, or hardware that creates, runs, and manages virtual machines (VMs) by abstracting the underlying physical hardware, allowing multiple operating systems to run on a single host machine simultaneously.

Microservices architecture decomposes a large application into a collection of small, independent services that communicate over well-defined APIs, each focusing on a specific business capability, enabling easier scaling, deployment, and maintenance compared to monolithic designs.

CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) presents challenges like image recognition or distorted text that are easy for humans but difficult for bots, preventing automated abuse such as spam or fake account creation on websites.

A switch-case statement allows a variable to be tested against a list of values, executing different code blocks based on the match, providing an efficient alternative to multiple if-else statements for handling numerous discrete conditions.

A DoS attack floods a target system, network, or website with excessive traffic or requests, consuming resources and making it unavailable to legitimate users, often used maliciously to cause downtime or as a smokescreen for other attacks.

Holographic storage uses laser interference patterns to store data in three-dimensional volumes within a photosensitive material, allowing massive parallel access and high-density storage far beyond traditional 2D optical discs.

A CDN distributes content across a global network of edge servers, caching data closer to users to reduce latency, improve load times, and handle traffic spikes, enhancing user experience for websites and streaming services.

XML (eXtensible Markup Language) is a flexible markup language used to structure, store, and transport data with custom tags, unlike programming languages like Java, Python, or C# which execute logic and computations.

A packet sniffer (or analyzer) intercepts and logs network traffic data packets, allowing inspection of headers, payloads, and protocols for troubleshooting, security monitoring, or performance optimization in networks.

The Network Access layer in TCP/IP (combining OSI's Physical and Data Link layers) handles hardware addressing, physical transmission, and media access, directly corresponding to the OSI Physical layer's bit-level signaling and cabling.

Genetic algorithms mimic natural evolution through selection, crossover, and mutation to iteratively search for optimal solutions in complex, multi-variable problems like scheduling or design optimization in AI.

Wearables like smartwatches or fitness trackers are designed to be embedded in or attached to clothing/accessories for seamless, hands-free use, collecting real-time data such as health metrics while remaining portable and unobtrusive.

Semaphores are synchronization primitives that use counters to manage concurrent access to shared resources, preventing race conditions by signaling processes when resources are available or locked.

Gamification incorporates game mechanics like points, badges, and leaderboards into educational content to boost learner motivation, engagement, and retention by making abstract or repetitive tasks more interactive and rewarding.

A gateway translates protocols between dissimilar networks (e.g., LAN to WAN), enabling communication by performing protocol conversion, routing, and sometimes security functions at the network boundary.

Spear phishing is a targeted phishing variant that crafts personalized emails or messages to specific high-value individuals (e.g., executives) to extract sensitive information, unlike broad phishing or malware like adware/spyware/trojans.

A profiler instruments code to measure execution time, memory usage, and resource consumption, pinpointing inefficient sections (bottlenecks) for optimization, improving overall application speed and efficiency.

Clustered file systems distribute data across multiple interconnected nodes for high availability, scalability, and parallel access, allowing shared storage in environments like HPC or cloud computing.

A honeypot is a decoy system designed to lure attackers, capturing their tactics, tools, and methods for analysis, helping improve defenses without risking real assets.

Hadoop is an open-source framework for distributed storage and processing of large-scale data sets across clusters using HDFS for storage and MapReduce for parallel computation, ideal for big data analytics.

The Session layer (OSI Layer 5) handles setup, coordination, and termination of communication sessions between applications, ensuring dialog control, synchronization, and recovery from disruptions.

Serverless computing (e.g., AWS Lambda) abstracts server management, automatically scaling and provisioning resources based on demand, allowing developers to focus on code without infrastructure concerns.

Firmware rollback restores a device's low-level software to a prior stable version if an update introduces bugs or instability, ensuring functionality and data integrity in embedded systems.

Continuous Integration (CI) automates merging code changes into a shared repository with immediate testing, detecting integration errors early, improving code quality, and accelerating release cycles.

A parity bit adds redundancy to binary data by setting it so the total number of 1s is even (even parity) or odd (odd parity), allowing the receiver to detect single-bit transmission errors.

SDN separates the control plane (centralized software controller) from the data plane (hardware switches), enabling programmable, dynamic network management for better automation and efficiency.

Coroutines allow functions to pause and resume execution cooperatively, yielding control without preemption, facilitating lightweight multitasking in languages like Python or Lua for tasks like generators or async I/O.

BMP (Bitmap) is a raster format storing images as pixel grids, suitable for detailed photos but losing quality when scaled, unlike vector formats like SVG, AI, or EPS which use mathematical paths.

A testbed is an isolated setup with hardware, software, and data mimicking production to safely test new features, integrations, or fixes, identifying issues without affecting live systems.

Mesh topology connects nodes directly to multiple others, providing redundant paths for resilient communication, self-healing, and high throughput, though complex to implement compared to star or bus.

A watchdog timer is a hardware counter that resets the microcontroller if not periodically serviced (e.g., by a heartbeat signal), preventing hangs or crashes in real-time embedded applications.

Containerization (e.g., Docker) packages applications with dependencies into isolated, lightweight units sharing the host OS kernel, ensuring consistency across environments and efficient resource use.

A nonce (number used once) is a random or sequential value included in cryptographic protocols to ensure message uniqueness, thwarting replay attacks where intercepted data is resent maliciously.

Fog computing extends cloud capabilities to the network edge (e.g., IoT gateways), processing data locally near sources to reduce latency, bandwidth use, and cloud dependency in time-sensitive applications.

In RPC (Remote Procedure Call), a stub on the client marshals arguments and invokes the remote service transparently, while the server stub unmarshals and executes, abstracting network details for distributed programming.

Unix is a multi-user, time-sharing OS that allocates CPU time slices to multiple processes or users via scheduling, enabling concurrent interactive sessions, unlike single-user MS-DOS or firmware BIOS.

A data lake is a centralized repository for storing vast amounts of raw, unstructured, semi-structured, or structured data in native format until needed, supporting flexible big data analytics without predefined schemas.

Zero-trust assumes no implicit trust, requiring continuous verification of users, devices, and contexts via multi-factor authentication, micro-segmentation, and least privilege to mitigate insider and external threats.

The bus controller manages arbitration, timing, and protocol enforcement on the system bus, ensuring orderly data/address/control signal transfers between CPU, memory, and peripherals.

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