Comprehensive coverage of all computer science concepts from CompTIA A+ certification.
Proper procedures, communication, and safety measures in IT environments.
Learn MoreMaster the essential skills for maintaining safety, professionalism, and excellence in IT environments.
Master the art of technical translation by adapting your language to different audiences. For non-technical users, use simple analogies ("Think of RAM like a desk workspace - the bigger it is, the more projects you can have open at once"). For technical peers, be precise but concise. Always confirm understanding by asking follow-up questions like, "Does this make sense so far?" or "Would you like me to clarify any part of this?"
Professional writing follows the ABC principle: Accurate, Brief, Clear. Structure technical documentation with:
Effective updates follow the 4P framework:
What's been accomplished since last update
Current blockers or unexpected issues
Next steps and timeline
What do you need to do now
Practice the LARA method for effective dialogue:
Proper use of Anti-static mats, Wrist straps, and Anti-static bags when Handling / Storing or Shipping out sensitive components.
This is Greatly exaggerated in the IT / Tech world, Tho it is still a great risk that can occur
Acknowledgement of the nearest Fire exits, First Aid kits, and Emergency shutdown procedures.
Proper workstation setup to prevent, Disorganization and Misstakes from Misplaced Screws or Small Components to Incorrect Wiring or Memory Alignment .
Maintaining a good and consistant stance / back position to reduces and prevents straining injuries. This is common during Warehouse Tasks or Actively doing Heavy Manual labour .
Make sure to use Safe lifting techniques and to know your limit. (Most of us are not Superman).
This is to ensure proper safe storage of hardware and to prevent injuries and Breaking Components.
Protect: Customer data, passwords, and proprietary information. GDPR/HIPAA compliance ? Secure file disposal ? Need-to-know access
Maintain: Truthful time reporting, accurate documentation, and transparent limitations. Disclose conflicts ? Reject bribes ? Credit others' work
Own: Mistakes, system changes, and security incidents. Change logs ? Incident reports ? RCA documentation
Consider: Environmental impact, accessibility, and digital divide. E-waste recycling ? WCAG compliance ? Tech literacy programs
Adhere to: Licensing, copyright, and regulatory requirements. Software licenses ? Patent laws ? Export controls
Ensure: Algorithmic fairness, transparency, and human oversight. Bias testing ? Explainable AI ? Human-in-the-loop
Uphold: System reliability, data backups, and disaster recovery. 99.9% uptime ? Backup verification ? Disaster recovery drills
Pursue: Threat modeling, ethical hacking, and secure coding. CVE monitoring ? OWASP training ? Red team exercises
Always carry a professional toolkit including:
Understanding computer components, their connections, and how hardware and software work together.
Data moves through the system via buses and interfaces, with the CPU coordinating operations between components using electrical signals and binary code.
The power supply converts AC to DC power at various voltages needed by different components.
Universal Serial Bus (A, C, etc.)
Video/audio interface
RJ45 network connection
3.5mm audio connection
AC/DC power inputs
High-speed data/display
Look for distinctive shapes, colors, and symbols near ports. Modern motherboards often color-code ports.
Note: USB-C is reversible but not all USB-C ports support the same features (Thunderbolt, power delivery, etc.)
Windows, icons, menus, and pointer (WIMP) with desktop metaphor
Hierarchical directory structure with file explorer
Built-in TCP/IP stack and network configuration tools
Disk management, task manager, and control panel
Applications make system calls to the OS for resources
OS manages hardware through drivers and firmware
Middleware provides services between applications
Virtual machines and containers abstract the hardware
Full path from root
From current directory
Command Line Interface - text-based input with commands and parameters
Graphical User Interface - visual elements like windows and icons
Direct manipulation with gestures like tap, swipe, pinch
Natural User Interfaces using speech recognition
Windows 11 combines GUI (Start menu, windows) with touch (gestures), voice (Cortana), and CLI (PowerShell/WSL) for versatile interaction.
The brain of the computer that performs calculations and executes instructions.
From vacuum tubes in the 1940s to today's nanometer-scale transistors, CPUs have evolved dramatically.
Performs all arithmetic and logical operations including:
The conductor of the CPU orchestra:
CPU begins execution at a fixed memory address (0xFFFFFFF0 in x86) in ROM. The Power Good signal from PSU triggers this.
CPU executes BIOS/UEFI firmware to:
CPU loads bootloader via these steps:
CPU executes kernel startup:
When you click a browser icon:
Carries memory addresses from CPU to RAM. Width determines maximum addressable memory:
Transfers actual data between CPU and memory. Modern systems use 64-bit wide buses.
Carries signals like:
Modern CPUs can execute multiple instructions per cycle through:
Modern CPUs use deep pipelines (15-20 stages) to overlap execution:
Modern approaches to parallelism:
Check chipset support (Z790 vs B650) and BIOS requirements.
High-end CPUs may require 240mm+ AIO liquid coolers.
May require motherboard replacement if socket damaged.
Temporary storage that the CPU uses to store data that is actively being worked on.
RAM is volatile memory that provides fast temporary storage for data being actively used by the CPU.
Needs constant refreshing, used for main system memory.
Faster but more expensive, used for CPU cache.
Synchronous DRAM, first to sync with system bus
Double Data Rate, 2x transfer rate
Higher speeds, lower power
Higher bandwidth, 1.5V standard
Higher density, 1.2V standard
Doubled bandwidth, on-die ECC
Dual In-line Memory Modules used in desktop computers and servers.
133.35mm
288 (DDR4/DDR5)
Small Outline DIMMs used in laptops and compact systems.
67.6mm
260 (DDR4)
Power off and unplug the computer
Open the case and locate RAM slots
Push down the retention clips at each end
Align notch and firmly press until clips snap
Power off and remove battery if possible
Remove access panel or keyboard
Insert at 45? angle then press down
Reassemble and power on to verify
8GB
16GB
16-32GB
32GB+
Basic configuration with one RAM stick
Two identical sticks for 128-bit bus
High-end systems with four sticks
Check seating, try one stick at a time
Run memory diagnostics (Windows: mdsched.exe)
Verify running at correct speed in BIOS
ECC (Error Correcting Code) memory detects and fixes bit errors, used in servers and workstations.
Contains a register between RAM and memory controller for stability with large amounts of RAM.
Intel's Extreme Memory Profile for easy overclocking of supported RAM kits.
The bridge between hardware and operating systems across all platforms.
The traditional firmware interface found on older systems.
Modern firmware standard with enhanced capabilities.
Firmware handles low-level keyboard input during pre-boot environment.
// Common BIOS/UEFI Keys:
DEL/F2 - Setup
F8/F12 - Boot Menu
ESC - Exit
Non-volatile RAM stores system configuration.
Common Settings:
Power-On Self-Test verifies hardware before boot.
Beep Codes
1 long, 2 short: Video error
POST Cards
Hex codes for diagnostics
Ensures only signed OS loaders execute
Hardware-based encryption (Windows 11+ requirement)
Prevents unauthorized BIOS changes
PXE Boot (Enterprise):
Network boot using DHCP/TFTP
Common in data centers
Flashing BIOS
Update via USB or vendor tools (SUPERMICRO, ASUS)
Clearing CMOS
Jumper or battery removal resets settings
RTC Reset
Dead CMOS battery causes time reset
AMI BIOS Setup Utility
Main
Advanced
Boot
Security
Exit
System Time: [14:30:22]
System Date: [08/19/2025]
SATA Configuration
USB Configuration
Fan Speed Control
?? Select Item Enter Select +/- Change Values F1 Help ESC Exit
00/FF
Successful POST
C1
Memory error
D0
CPU failure
A2
IDE detect
Server POST Cards:
Supermicro boards display IPMI codes
ASUS servers use Q-Code displays
Try these in your BIOS/UEFI setup:
1. Document Settings
Note your current boot order and security settings
2. Change Boot Mode
Switch between Legacy and UEFI (if available)
3. Reset to Defaults
Load optimized defaults and observe changes
The main circuit board that connects all components of a computer system.
Essential components that make up a modern motherboard.
Historically handled high-speed CPU connections.
Handled slower I/O operations.
Most functions now integrated into CPU.
Components that convert AC power to DC and distribute it to computer components.
Important specifications when selecting a power supply.
Main motherboard power connector.
CPU power connector.
Graphics card power connector.
Devices and technologies for long-term data storage.
Magnetic storage with spinning platters for high-capacity storage.
Flash memory with no moving parts for faster performance.
Serial ATA for HDDs and SATA SSDs (6Gbps).
PCIe-based interface for high-speed SSDs (up to 32Gbps).
Form factor supporting both SATA and NVMe SSDs.
Techniques for configuring and managing storage devices.
Different RAID levels offer various balances of performance, capacity, and redundancy.
Master Boot Record (legacy, max 2TB).
GUID Partition Table (modern, >2TB).
NTFS, FAT32, exFAT, ext4, APFS.
Input and output devices that extend computer functionality.
Devices used to input data and commands into the computer.
Devices that display or output information from the computer.
Universal Serial Bus (USB-A, USB-C, USB 2.0/3.0/4).
Wireless standard for short-range communication.
Legacy port for keyboards and mice.
Methods and considerations for installing and upgrading operating systems.
Different ways to install an operating system.
TPM 2.0, Secure Boot, 4GB RAM, 64GB storage.
Apple hardware, 4GB RAM, 35GB storage.
Varies by distro, typically 2GB RAM, 25GB storage.
Navigating and configuring operating system settings and features.
Tools and techniques for managing files and folders.
Monitor and manage running processes (Windows).
Monitor system resources (macOS).
Linux equivalent for process management.
Managing user accounts, groups, and access control in operating systems.
User account types in Windows operating systems.
User account types in Unix-based systems.
Windows file system permissions (Full Control, Modify, etc.).
Unix/Linux permission system (rwx for user/group/others).
Windows domain-level permission management.
Techniques for keeping operating systems running smoothly and efficiently.
Regular tasks to keep the OS performing well.
Controlling which applications launch at startup.
Disabling unnecessary background services.
Adjusting page file settings for optimal performance.
Powerful text-based interface for interacting with operating systems.
Command-line tools available in Windows.
Terminal environments in Unix-based systems.
ls/dir, cd, cp/copy, mv/move, rm/del
top/tasklist, df, free, systeminfo
ping, ipconfig/ifconfig, netstat, traceroute
Diagnosing and resolving common operating system issues.
Systematic approach to identifying and resolving issues.
Missing OS, corrupt bootloader, hardware issues.
High CPU/memory usage, disk bottlenecks.
Compatibility issues, missing dependencies.
Understanding monitor types, resolutions, and display technologies.
Liquid Crystal Display variants and their characteristics.
HD (720p), FHD (1080p), QHD (1440p), UHD (4K), 8K
60Hz, 120Hz, 144Hz, 240Hz, 360Hz
1ms, 4ms, etc. (lower is better)
Fundamental concepts of computer networking and communication.
7-layer conceptual model for network communications.
4-layer practical implementation model.
Connection-oriented vs connectionless.
IPv4 (32-bit) vs IPv6 (128-bit).
HTTP, HTTPS, FTP, SSH, DNS, DHCP.
Technologies and devices for connecting computers in a limited area.
Core components of a local area network.
Cat5e (1Gbps), Cat6 (10Gbps), Cat6a (10Gbps), Cat7 (10Gbps+).
Single-mode vs multi-mode, long-distance.
RJ45, LC, SC, ST.
Wi-Fi standards, security, and configuration for wireless networks.
Evolution of Wi-Fi technologies over time.
WEP (insecure), WPA, WPA2, WPA3.
PSK, 802.1X, Enterprise.
Strong passwords, disable WPS, hide SSID.
Global network of networks and the technologies that power it.
Entities that provide internet connectivity.
Domain Name System (name resolution).
IaaS, PaaS, SaaS deployment models.
CDNs for faster content distribution.
Creating virtual versions of hardware, operating systems, and other resources.
Running multiple operating systems on a single physical machine.
Better hardware utilization.
Separate environments for security/testing.
Easy to deploy new instances.
Laptops, tablets, and other mobile computing devices.
Components unique to or different in laptops.
Touchscreen, stylus, voice input.
Wi-Fi, Bluetooth, cellular options.
Expand functionality when stationary.
Smartphones, tablets, and other portable computing devices.
Dominant mobile operating systems and their characteristics.
Google Play Store, Apple App Store
Android Studio, Xcode, Flutter
Enterprise deployment, sideloading
Best practices for protecting mobile devices and their data.
Methods to verify user identity on mobile devices.
Centralized control of corporate devices.
Mobile Application Management.
Bring Your Own Device guidelines.
Printing technologies and multifunction device management.
Printers that use physical impact to create images.
Print, Scan, Copy, Fax
USB, Ethernet, Wi-Fi, Cloud
Print servers, quotas, auditing
Protecting systems from threats and vulnerabilities.
Various forms of malicious software.
Antivirus, Firewalls, Anti-malware
Password policies, access controls
Locks, biometrics, surveillance
IT documentation, change management, and best practices.
Critical documentation for IT operations.
Track issues and resolutions
Documented processes
Shared troubleshooting info
Explore how operating systems manage hardware resources and provide services to applications.
Microsoft's flagship OS with GUI focus and broad software compatibility.
Open-source kernel powering many distributions (Ubuntu, Fedora, etc.).
Apple's Unix-based OS with tight hardware-software integration.
New, Ready, Running, Waiting, Terminated
Round Robin, Priority, Shortest Job First, Multilevel Queue
Lightweight processes sharing the same memory space
Divides memory into fixed-size blocks called pages
Divides memory into variable-sized logical segments
Uses disk space to extend available RAM
Curated collection of resources to enhance your computer science journey.