Quick Revision

GK One-Line Question & Answer

15541+ short questions with short answers, covering every category and sub-category on the site — no long articles to scroll through. Good for a fast recap before an exam, or a few minutes of daily practice.

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Computer Fundamentals → Introduction to Computer 40

async/await in Python is based on?
Coroutines and event loop — cooperative multitasking
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Event loop in Node.js/JavaScript?
Single-threaded non-blocking I/O through callback/promise/async-await mechanism
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libuv library provides Node.js with?
Cross-platform asynchronous I/O and event loop
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V8 JavaScript engine is developed by?
Google — also used in Node.js
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JIT (Just-In-Time) compilation?
Compiles frequently executed code at runtime to machine code
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Garbage collection (GC) in managed languages?
Automatically reclaims unused memory
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Mark-and-sweep GC algorithm?
Marks reachable objects, sweeps (frees) unmarked objects
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Reference counting GC fails with?
Circular references — objects referencing each other never reach count zero
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Generational GC is based on the observation that?
Most objects die young — frequent minor GC of young generation, rare major GC
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Concurrent GC (like Go's GC) runs?
Concurrently with the application, minimizing stop-the-world pauses
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LLVM is?
Compiler infrastructure providing reusable compiler and toolchain components
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Clang is?
C/C++/Objective-C compiler using LLVM backend
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Rust programming language is notable for?
Memory safety without GC using ownership/borrowing system
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Rust's ownership system ensures?
At most one mutable reference OR multiple immutable references at any time — preventing data races
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WebAssembly (WASM) is?
Binary instruction format for stack-based VM running in browsers at near-native speed
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Microarchitecture simulator is used for?
Modeling CPU behavior cycle-accurately for architectural research
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Emulation vs simulation: emulation?
Reproduces exact behavior of another system on different hardware (functional)
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QEMU is used for?
Machine emulation and virtualization (full system emulation)
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KVM (Kernel-based Virtual Machine) in Linux is?
Type 1 hypervisor built into Linux kernel — uses hardware virtualization
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Intel VT-x and AMD-V are?
CPU hardware virtualization extensions enabling efficient hypervisors
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IOMMU (Intel VT-d / AMD-Vi) enables?
Secure direct device assignment to VMs — DMA protection
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Live migration of VMs transfers?
Running VM state (memory, CPU) to another host with minimal downtime
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Memory ballooning in virtualization?
Dynamically adjusts VM memory allocation by inflating/deflating balloon driver
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Memory deduplication (KSM in Linux) saves memory by?
Identifying identical memory pages across VMs and sharing them (Copy-on-Write)
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SR-IOV (Single Root I/O Virtualization) allows?
Physical NIC to present multiple virtual functions (VFs) for direct VM assignment
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DPDK (Data Plane Development Kit) enables?
User-space packet processing bypassing kernel for high-performance networking
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XDP (eXpress Data Path) in Linux provides?
High-performance packet processing in the kernel driver layer using eBPF
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P4 programming language is used for?
Programming the data plane of network devices (packet processing logic)
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SmartNIC (DPU) offloads to the NIC?
Networking, security, and storage functions from the CPU
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In-band network telemetry (INT) collects?
Per-packet path and queue data embedded in data plane packets
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Network digital twin provides?
Virtual replica of network for simulation, testing, and what-if analysis
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Zero-touch provisioning (ZTP) automates?
New device boot and configuration from central server without manual intervention
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GitOps applies Git workflows to?
Infrastructure and network configuration management — Git as single source of truth
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Service mesh data plane proxies like Envoy handle?
Inter-service traffic — load balancing, retries, circuit breaking, observability
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Istio service mesh uses Envoy as?
Data plane sidecar proxy injected alongside each service
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mTLS (Mutual TLS) in service mesh provides?
Both client and server authenticate each other — service-to-service identity
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Service Account in Kubernetes provides?
Identity for pods to authenticate with Kubernetes API and other services
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RBAC in Kubernetes controls?
Who can perform which actions on which resources in the cluster
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Pod Security Standards (PSS) in Kubernetes define?
Security contexts and constraints for pod workloads (privileged, baseline, restricted)
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OPA (Open Policy Agent) provides?
Policy-as-code for unified authorization across cloud-native stack
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