Hardware & Operating Systems Interview Review

Comprehensive vocabulary flashcards covering hardware components, storage types, RAID levels, startup processes, virtualization, and fiber optic basics for IT interview preparation.

Motherboard

The main circuit board that connects all computer components like the CPU, RAM, and storage.

CPU (Central Processing Unit)

The 'brain' of the computer that fetches, decodes, and executes instructions while coordinating system resources.

RAM (Random Access Memory)

Volatile temporary memory used by the CPU to store active data and applications; data is lost when power is removed.

SSD (Solid State Drive)

A storage device that uses flash memory with no moving parts, offering faster performance and higher reliability than HDDs.

HDD (Hard Disk Drive)

A storage device using mechanical spinning magnetic platters and moving heads; it is generally cheaper per GB but slower than SSDs.

NVMe (Non-Volatile Memory Express)

A communication interface and driver that allows high-speed SSDs to use PCIe lanes for significantly faster performance than SATA SSDs.

PSU (Power Supply Unit)

A component that converts AC power from the wall into DC power (typically $12V$, $5V$, and $3.3V$) used by computer components.

CMOS (Complementary Metal-Oxide-Semiconductor)

A component on the motherboard that stores BIOS settings, maintains the system clock, and requires a battery to keep data when powered off.

DDR4

A generation of RAM that is faster, has lower power consumption, and supports higher capacities compared to DDR3.

RAID (Redundant Array of Independent Disks)

A technology used to combine multiple physical disks for improved performance, redundancy, or both.

RAID 0

Striping; provides the fastest performance by spreading data across disks but offers no fault tolerance.

RAID 1

Mirroring; provides excellent redundancy by duplicating the same data on two or more disks.

RAID 5

Striping with parity; provides a balance of performance and redundancy, capable of surviving the failure of one drive.

RAID 6

A RAID level using double parity that can survive the simultaneous failure of two drives.

RAID 10

A combination of RAID 1 (mirroring) and RAID 0 (striping) that provides both high performance and fault tolerance.

BIOS (Basic Input/Output System)

Firmware that initializes hardware, runs POST, finds the boot device, and starts the operating system.

POST (Power-On Self-Test)

A hardware diagnostic test performed by the BIOS before the OS loads to check the health of the CPU, RAM, and storage.

UEFI (Unified Extensible Firmware Interface)

The modern replacement for BIOS that supports faster booting, Secure Boot, and larger disk capacities using GPT.

Operating System (OS)

Software that manages hardware resources, processes, memory, files, and applications (e.g., Windows, Linux, macOS).

GUI (Graphical User Interface)

A visual way of interacting with a computer using icons, windows, menus, and buttons instead of a command line.

Virtualization

The process of running multiple virtual machines on a single physical machine using software like VMware, Hyper-V, or VirtualBox.

Single-Mode Fiber (SMF)

Fiber optic cable with a small core (9 ̄̄ ̄̄̄̄ ̄̄̄̄ ̄̄̄ ̄Ź m) used for long-distance communication via laser light; usually yellow.

Multimode Fiber (MMF)

Fiber optic cable with a larger core (50/62.5 ̄̄ ̄̄̄̄ ̄̄̄̄ ̄̄̄ ̄គ m) used for shorter distances within buildings; usually orange or aqua.

GPU (Graphics Processing Unit)

A processor with thousands of smaller cores optimized for parallel processing tasks like graphics, AI, and machine learning.

DIMM (Dual In-line Memory Module)

The physical memory module or 'stick' that contains RAM chips and is installed into the motherboard.

ROM (Read-Only Memory)

Non-volatile memory used to store firmware and boot instructions that are not lost when power is removed.

PXE Boot

Preboot Execution Environment; used for automated OS deployment across multiple machines over a network.

Load Balancer

A device that distributes incoming traffic across multiple servers to ensure high availability and prevent overload.

BMC / iDRAC / iLO

Out-of-band management systems that allow administrators to monitor and manage servers even if the OS is not running.

Fiber Connectors (LC, SC, ST, MPO)

The physical interfaces for fiber cables; LC is most common in data centers, while MPO/MTP is used for high-density $40G/100G/400G$ environments.