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 39

Lateral movement in cyberattacks refers to?
Moving through network from initial foothold to more valuable targets
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APT (Advanced Persistent Threat) is characterized by?
Long-term, sophisticated, targeted intrusion campaigns
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IOC (Indicator of Compromise) examples include?
Suspicious IPs, file hashes, domain names indicating breach
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MITRE ATT&CK framework documents?
Real-world adversary tactics, techniques, and procedures (TTPs)
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Threat modeling process identifies?
Potential threats, vulnerabilities, and countermeasures during design
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STRIDE threat model acronym stands for?
Spoofing, Tampering, Repudiation, Information disclosure, Denial of service, Elevation of privilege
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Data Loss Prevention (DLP) prevents?
Unauthorized transmission or exfiltration of sensitive data
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SIEM (Security Information and Event Management) provides?
Centralized security event correlation, analysis, and alerting
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SOAR (Security Orchestration, Automation, and Response) adds to SIEM?
Automated incident response workflows
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Zero Trust security model assumes?
No implicit trust — verify every access request regardless of location
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Copy-on-Write (CoW) in OS fork() means?
Parent and child share memory pages until one writes — then copy
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Memory-mapped files allow?
Files to be accessed as if they were in memory (mmap)
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Page table walk in x86-64 uses how many levels?
4
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TLB (Translation Lookaside Buffer) caches?
Virtual-to-physical address translations
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TLB shootdown occurs when?
One CPU modifies page tables requiring other CPUs to invalidate their TLBs
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Huge pages (large pages) reduce?
TLB misses by covering larger address ranges per entry
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mlock() system call in Linux?
Locks pages in RAM (prevents swapping to disk)
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cgroup (control groups) in Linux is used for?
Resource limiting, accounting, isolation for process groups
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Linux namespace provides?
Process isolation — separate view of system resources (PID, NET, MNT, etc.)
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seccomp in Linux is used to?
Filter system calls available to a process (sandbox)
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SELinux implements?
Mandatory Access Control (MAC) based on security policies
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AppArmor is an alternative to SELinux implementing?
MAC using file path-based profiles
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eBPF (extended Berkeley Packet Filter) allows?
Safe kernel-level programmability without modifying kernel source
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Which scheduling policy is used for real-time tasks in Linux?
SCHED_FIFO or SCHED_RR
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I/O scheduler in Linux determines?
Order and priority of I/O requests to storage devices
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Which I/O scheduler is best for SSDs?
None/mq-deadline
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Futex (Fast Userspace muTEX) in Linux?
Operates mostly in userspace — falls to kernel only on contention
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Lock-free data structures use?
Atomic operations to ensure thread safety without locks
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ABA problem in lock-free programming occurs when?
Value changes A→B→A appearing unchanged to CAS, causing incorrect operation
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B+ tree advantages over B-tree for database indexing?
All data in leaf nodes + linked leaves enable efficient range queries
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LSM tree (Log-Structured Merge tree) is used in?
Write-optimized databases like LevelDB, RocksDB, Cassandra
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Skip list provides?
O(log n) average search with probabilistic balance (simpler than balanced BST)
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Consistent hashing is used in?
Distributed systems for even load distribution as nodes join/leave
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CAP theorem states a distributed system can guarantee only two of?
Consistency, Availability, Partition tolerance
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In CAP theorem, CP system prioritizes?
Consistency and Partition tolerance — may be unavailable during partition
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AP system in CAP theorem?
Prioritizes Availability and Partition tolerance — may return stale data
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PACELC theorem extends CAP by also considering?
Latency vs Consistency tradeoff when no partition exists
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MapReduce programming model consists of?
Map phase (parallel processing) + Reduce phase (aggregation)
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Apache Hadoop uses MapReduce on?
HDFS distributed file system across cluster
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Computer Fundamentals → Memory Units 1

Which OS feature isolates processes from each other?
Process isolation via separate virtual address spaces
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