Professor Messer's CompTIA 220-1201 Core 1 A+ Vocabulary

Flashcards covering key hardware, networking, mobile device, storage, virtualization, and troubleshooting terminology from Professor Messer's CompTIA 220-1201 Core 1 A+ Course Notes.

Tone generator and inductive probe

A two-piece network tool set where one device places an analog audio signal on a copper wire and the inductive probe detects the audio tone to trace the cable without touching the wire.

Lucent Connector (LC), Straight Tip (ST), and Subscriber Connector (SC)

Common optical fiber connectors: LC uses a small push-pull retaining clip, ST uses a bayonet stick-and-twist lock, and SC uses a square push-pull locking mechanism.

Punch-down tool

A hand tool used to insert and trim individual copper wires into wiring blocks such as 66 blocks or 110 blocks.

Cable crimper

A networking tool used to press metal prongs through wire insulation to secure modular connectors such as RJ45 or RJ11 onto twisted-pair cables.

Hard Disk Drive (HDD) internal components

Mechanical internal parts of a traditional magnetic drive, including spinning platters, a spindle, an actuator arm, an actuator, and a read/write head.

Molex connector

A 4-pin peripheral power connector providing $+12\,V$ and $+5\,V$ DC power from the power supply to computer components such as storage drives and fans.

Optical fiber cable layers

Structure of a fiber optic cable, consisting of a central light-transmitting core, cladding that reflects light back into the core, and an outer protective coating.

SO-DIMM

Small Outline Dual In-line Memory Module; a compact RAM form factor used primarily in laptops and mobile devices.

Near-field communication (NFC)

A short-distance wireless networking standard (4 centimeters or less) used for mobile payments, authentication, and simple data transfers.

Transmission Control Protocol (TCP)

A connection-oriented, reliable Layer 4 protocol that manages formal connection setup/close, error recovery, retransmissions, and flow control.

User Datagram Protocol (UDP)

A connectionless, unreliable Layer 4 protocol with no error recovery or flow control, used for real-time traffic like voice and DHCP.

FTP (File Transfer Protocol)

A network service used to transfer files between systems, operating on tcp/20 for active mode data and tcp/21 for control commands.

SSH (Secure Shell)

An encrypted terminal communication link protocol operating over tcp/22.

DNS (Domain Name System)

A hierarchical distributed database system operating over udp/53 that converts human-readable domain names into IP addresses.

DHCP (Dynamic Host Configuration Protocol)

An automated network service operating over udp/67 and udp/68 that assigns IP addresses, subnet masks, default gateways, and DNS configuration to clients.

SMB (Server Message Block)

A Microsoft Windows file and printer sharing protocol operating directly over tcp/445 or via NetBIOS over TCP/IP.

DORA

The four-step DHCP lease process consisting of Discover, Offer, Request, and Acknowledge.

APIPA (Automatic Private IP Addressing)

A link-local IPv4 address block ($169.254.0.0/16$) automatically assigned by an operating system when a DHCP server cannot be reached.

Trusted Platform Module (TPM)

A dedicated cryptographic processor embedded on a computer motherboard that securely generates and stores encryption keys, certificates, and passwords for a single device.

Hardware Security Module (HSM)

A high-end dedicated cryptographic hardware appliance or plug-in card used in enterprise environments to manage and back up cryptographic keys across multiple devices.

RAID 0

Disk striping across two or more physical drives to improve performance, offering zero redundancy (a single drive failure destroys the array).

RAID 1

Disk mirroring across two or more physical drives to provide redundancy by duplicating all written file blocks.

RAID 5

Disk striping with single parity across a minimum of three physical drives, providing redundancy and allowing data recovery if one drive fails.

RAID 6

Disk striping with dual parity across a minimum of four physical drives, allowing the array to withstand up to two simultaneous drive failures.

Single-mode Fiber

Optical fiber cabling that uses a laser light source for long-range communications up to 100 kilometers without signal processing.

Multimode Fiber

Optical fiber cabling that uses an LED light source for short-range communications up to 2 kilometers.

ECC (Error Correcting Code) Memory

Specialized RAM used in critical servers that can detect memory errors and correct single-bit errors on the fly.

IPS (In Plane Switching) LCD

An LCD panel technology offering superior color representation and wide viewing angles, but generally more expensive to produce than Twisted Nematic (TN) panels.

OLED (Organic Light Emitting Diode)

A display technology using organic compounds that emit light directly when electrical current is applied, requiring no backlight.

Secure Boot

A UEFI BIOS protection standard that cryptographically checks digital signatures of bootloaders and drivers to prevent unauthorized software execution during startup.

Infrastructure as a Service (IaaS)

A cloud service model where equipment and infrastructure are outsourced to a vendor, but the client manages operating systems, applications, and data security.

Software as a Service (SaaS)

A cloud service model providing complete, vendor-managed applications on demand over the internet without requiring local installation or software maintenance.

Platform as a Service (PaaS)

A cloud service model where a vendor manages the underlying platform infrastructure and OS, allowing clients to build and manage custom applications using modular tools.

Category 6 Cable (Cat 6)

An Ethernet twisted-pair cabling standard supporting 10GBASE-T up to 55 meters unshielded or 100 meters shielded.

CNAME Record

A Canonical Name record in DNS that aliases one domain name to another canonical domain name.

MX Record

A Mail Exchanger record in DNS that specifies the host name of the mail server responsible for receiving emails for a domain.

Power over Ethernet (PoE)

An IEEE 802.3 standard technology that delivers electrical DC power along with network data over Ethernet cabling to devices such as IP phones and wireless access points.