CompTIA A+ Complete Practice Tests Overview

FTP (File Transfer Protocol)

Uses ports 20 (data) and 21 (control) to transfer files between a client and server.

SSH (Secure Shell)

Uses port 22 to provide a secure, encrypted terminal connection to a remote host.

Telnet

Uses port 23 to provide an unencrypted remote login service; generally insecure and replaced by SSH.

SMTP (Simple Mail Transfer Protocol)

Uses port 25 for sending email between servers.

DNS (Domain Name System)

Uses port 53 to resolve hostnames (like google.com) to IP addresses.

HTTP (Hypertext Transfer Protocol)

Uses port 80 for unencrypted web traffic.

POP3 (Post Office Protocol v3)

Uses port 110 to retrieve email from a server; typically deletes the mail from the server after download.

IMAP (Internet Message Access Protocol)

Uses port 143 to retrieve email; synchronizes mail across multiple devices.

HTTPS (HTTP Secure)

Uses port 443 for encrypted web traffic using TLS/SSL.

RDP (Remote Desktop Protocol)

A Microsoft proprietary protocol using port 3389 for remote GUI access to Windows machines.

NetBIOS/NetBT

Uses ports 137 through 139 for legacy Windows name resolution and session services.

SMB/CIFS (Server Message Block)

Uses port 445 for Windows file and printer sharing on modern networks.

SLP (Service Location Protocol)

Uses port 427 to find services on a local area network without prior configuration.

AFP (Apple Filing Protocol)

Uses port 548 for file transfers on macOS systems.

DHCP (Dynamic Host Configuration Protocol)

Uses ports 67 and 68 to automatically assign IP addresses and network configuration to clients.

LDAP (Lightweight Directory Access Protocol)

Uses port 389 to query and modify information in directory services like Active Directory.

SNMP (Simple Network Management Protocol)

Uses ports 161 and 162 to monitor and manage network devices.

Cat 5 Cable

Rated for 100 ext{ Mbps} at a frequency of 100 ext{ MHz}.

Cat 5e Cable

Enhanced version of Cat 5 rated for 1 ext{ Gbps} at 100 ext{ MHz}.

Cat 6 Cable

Rated for 10 ext{ Gbps} up to 55 ext{ meters} and 1 ext{ Gbps} up to 100 ext{ meters}.

Cat 6a Cable

Augmented version of Cat 6 rated for 10 ext{ Gbps} up to 100 ext{ meters}.

T568A vs. T568B

Two standards for terminating RJ45 connectors; T568B is the most common in commercial installations.

Single-Mode Fiber (SMF)

Uses laser light to transmit data over very long distances (kilometers).

Multi-Mode Fiber (MMF)

Uses LED light for shorter distances (up to 2 ext{ km}), common in data centers.

RG-6 Coaxial Cable

Thicker cable used for modern cable TV and high-speed internet.

RG-59 Coaxial Cable

Thinner cable used for short-distance video (like older CCTV systems).

OSI Layer 1: Physical

Handles cables, connectors, and the transmission of raw bits.

OSI Layer 2: Data Link

Handles MAC addresses, switches, and frames.

OSI Layer 3: Network

Handles IP addresses, routers, and packets.

OSI Layer 4: Transport

Handles TCP/UDP protocols, port numbers, and segments.

Hub

A layer 1 device that broadcasts traffic to all ports; inefficient and prone to collisions.

Unmanaged Switch

A layer 2 plug-and-play device with no configuration options.

Managed Switch

A layer 2 device that supports VLANs, SNMP, and advanced traffic control.

Router

A layer 3 device that routes traffic between different logical networks.

Wireless Access Point (WAP)

A device that allows wireless clients to connect to a wired network.

Patch Panel

A field of ports used to organize and terminate permanent cable runs.

PoE (Power over Ethernet)

Sends electrical power along with data over Ethernet cabling (802.3af/at).

Ethernet over Power (PLC)

Technique to send data over existing electrical wiring in a building.

802.11a

Wireless standard at 5 ext{ GHz}, 54 ext{ Mbps}. Not compatible with b/g.

802.11b

Wireless standard at 2.4 ext{ GHz}, 11 ext{ Mbps}. Uses DSSS.

802.11g

Wireless standard at 2.4 ext{ GHz}, 54 ext{ Mbps}. Backward compatible with 802.11b.

802.11n (Wi-Fi 4)

Wireless standard at 2.4 ext{ GHz} and 5 ext{ GHz}, up to 600 ext{ Mbps} using MIMO.

802.11ac (Wi-Fi 5)

Wireless standard at 5 ext{ GHz}, Multi-Gbps speeds using MU-MIMO.

WPA3

The latest wireless security standard using SAE (Simultaneous Authentication of Equals).

TKIP (Temporal Key Integrity Protocol)

Legacy encryption for WPA; now considered insecure.

AES (Advanced Encryption Standard)

The strong encryption standard used by WPA2 and WPA3.

Class A Private IP Range

10.0.0.0 to 10.255.255.255.

Class B Private IP Range

172.16.0.0 to 172.31.255.255.

Class C Private IP Range

192.168.0.0 to 192.168.255.255.

APIPA (Automatic Private IP Addressing)

Self-assigned IP range 169.254.x.x used when a DHCP server is unreachable.

Subnet Mask

Determines which part of an IP address is the network and which part is the host.

Default Gateway

The router address a computer uses to access the internet or other networks.

DORA Process

The 4-step DHCP process: Discover, Offer, Request, Acknowledge.

DDR4 RAM

Uses a 288-pin interface and supports higher speeds and densities than DDR3.

DDR5 RAM

The latest RAM standard with on-die ECC and dual 32-bit channels per module.

Virtual Memory (Paging File)

Area on the storage drive used as an extension of physical RAM.

NVMe (Non-Volatile Memory Express)

High-speed protocol for SSDs using the PCIe bus.

SATA Revision 3.0

Interface for HDDs and SSDs with a maximum throughput of 6 ext{ Gbps}.

RAID 0 (Striping)

Requires 2 disks; improves performance but provides no redundancy.

RAID 1 (Mirroring)

Requires 2 disks; duplicates data for redundancy.

RAID 5 (Striping with Parity)

Requires 3 disks; provides redundancy and performance.

RAID 10 (Stripe of Mirrors)

Requires 4 disks; combines the speed of RAID 0 with the redundancy of RAID 1.

ATX (Advanced Technology eXtended)

The most common motherboard form factor (12 imes 9.6 ext{ inches}).

Micro-ATX

Smaller motherboard form factor (9.6 imes 9.6 ext{ inches}) designed to fit in ATX cases.

Mini-ITX

Smallest common motherboard form factor (6.7 imes 6.7 ext{ inches}).

BIOS vs. UEFI

UEFI is the modern replacement for BIOS, supporting Secure Boot and larger drives (2+ ext{ TB}).

Secure Boot

A UEFI security standard that ensures only digitally signed firmware and OS loaders run.

TPM (Trusted Platform Module)

Chip on the motherboard used for hardware-based encryption keys (required for Windows 11).

POST (Power-On Self-Test)

Diagnostic testing sequence run by BIOS/UEFI when a computer is turned on.

LGA vs. PGA

LGA (pins on motherboard) is used by Intel; PGA (pins on CPU) is used by AMD.

Thermal Paste

Fills microscopic gaps between the CPU and heat sink to improve heat transfer.

PSU Efficiency Ratings

Classified by 80 Plus standards (Bronze, Silver, Gold, Platinum, Titanium).

HDMI (High-Definition Multimedia Interface)

Digital interface for high-definition video and audio.

DisplayPort

Digital display interface often used for high-refresh-rate gaming monitors.

VGA (Video Graphics Array)

Legacy 15-pin analog video interface.

Bluetooth Range Class 2

The most common mobile standard with a range of approx. 10 ext{ meters}.

NFC (Near-Field Communication)

Wireless technology with a range of 10 ext{ cm} used for payments and pairing.

SaaS (Software as a Service)

Cloud model where applications are accessed via a browser (e.g., Google Workspace).

PaaS (Platform as a Service)

Cloud model providing a platform for developers to build/test apps (e.g., Heroku).

IaaS (Infrastructure as a Service)

Cloud model providing virtualized hardware, storage, and networking (e.g., AWS).

Public Cloud

Shared infrastructure accessible over the public internet.

Private Cloud

Infrastructure dedicated to a single organization, often hosted on-premises.

Rapid Elasticity

Cloud characteristic allowing quick scaling of resources up or down.

Resource Pooling

Cloud characteristic where provider resources are shared across multiple customers.

VDI (Virtual Desktop Infrastructure)

Hosting user desktops on a centralized server environment.

Type 1 Hypervisor

Bare-metal hypervisor running directly on hardware (e.g., ESXi, Hyper-V).

Type 2 Hypervisor

Hosted hypervisor running on top of an OS (e.g., VirtualBox, VMware Workstation).

S.M.A.R.T.

Self-Monitoring, Analysis, and Reporting Technology for assessing drive health.

Blue Screen of Death (BSOD)

Windows error screen indicating a multi-faceted system crash or hardware failure.

safe mode

Windows diagnostic boot mode that loads only the minimum required drivers.

ipconfig /all

Command to display detailed TCP/IP configuration for all network adapters.

ping

Utility used to test reachability and latency of a host over an IP network.

tracert

Command showing the path (hops) a packet takes to reach a destination.

nslookup

Command used to query DNS information and verify hostname resolution.

Mantraps

Physical security measure consisting of two interlocking doors to prevent tailgating.

Phishing

Social engineering via email designed to steal credentials or data.

Ransomware

Malware that encrypts user data and demands payment for the decryption key.

Principle of Least Privilege

Security concept of providing only the minimum permissions required for a task.

BitLocker

Windows feature used for full disk encryption.

MSDS / SDS

Safety documentation detailing chemical hazards and handling instructions.