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The CompTIA glossary

Clear definitions for the 1,414 terms, acronyms, and concepts you'll meet on the CompTIA A+, Network+, and Security+ exams — every one with a detailed explanation.

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Cloud Computing9

AWS Azure cloud applications cloud backups cloud dependency cloud platforms cloud services hosted services sla

Database37

General1

INSERT

Hardware887

10,000 RPM 100BASE-TX 10BASE-T 12V 12VHPWR 15,000 RPM 16x 2.5-inch 220-1201 24-pin 24x 256-QAM 2G 3-pin 3.3V 3.5-inch 4-pin 5,400 RPM 5G 5V 5V logic 6-pin PCIe 7,200 RPM 75-ohm terminators 8-pin PCIe 9-pin A-GPS AC AC adapter AC power AC signals accelerometers access point Accessory connection active stylus ADF Advanced RISC Machine AFC AGP airflow AirPrint alternating current Alternative A Alternative B AM4 AM5 AMD-V analog television signal analog voice signals Angle of Arrival Angled Physical Contact antenna performance APC connector Apple Pay ARM Asymmetric DSL atomic clock attenuation ATX ATX connector audio jack backlight backplane backward compatibility banding Barracuda Email Security Gateway base station battery backup unit Battery Efficiency BBU BD-R BD-RE beep codes Biometric Verification BIOS BIOS update black mark sensor BLE blower fans Blu-ray blue screens Bluetooth Bluetooth 4.0 Bluetooth 5.2 Bluetooth codecs Bluetooth LE Audio Bluetooth Low Energy Bluetooth profiles Bluetooth Tethering BNC BPSK bridged taps broadcast television buffer burn-in BYOD C rating cable modem cable nodes cable stripper cable television cable tester cache CAM table capacitive stylus capacitive touch capture cards capture devices carriage CAS latency Cat5e Cat6 Category 5e Category 6 Category 6a Category 7 Category 7a Category 8 CCFL backlight CD CD-R CD-RW CDMA CEC cell site cell tower Cell Tower Triangulation Cellular Data cellular internet cellular radios centrifugal fans channel bonding channel configurations channel width Charge Cycle Charging chip revision chipset chkdsk Cisco Meraki MX CL CMG CMP CMR CMTS CO coax coaxial cable color gamut COM port communication infrastructure community antenna television CompTIA A+console connections console port Contactless Payments COPE copper line path copper telephone lines copper-based cabling coulomb counting CPE CPU CPU architecture crimper CUPS customer premises equipment cutter area DAC daisy-chaining data bus width data rate Data transfer daughterboard DB25 DB9 DC DC power DC voltage DDR DDR generations DDR2 DDR3 DDR4 DDR5 Demarc demarcation point desktop computer device drivers Device Manager dial-up modem digital data digital signals Digital Subscriber Line Access Multiplexer digital television digitizer DIMM direct current direct thermal printing direct-lit Discoverable Mode dish antenna Disk Management DisplayPort distributed file systems docking docking station DOCSIS DOCSIS 3.0 dot matrix printer DP Alt Mode DPI draft mode driver driver control driver issues driver signing drivers drop line DSL DSL Filters DSL modem DSL signal DSL Splitters DSLAM DSSS Dual In-line Memory Module Dual-Channel dual-channel memory dual-link dual-slot duplex DVD DVD-R DVD-RW DVD+R DVD+RW DVI DVI-D DVI-I eARC ECC ECC vs. non-ECC RAM edge-lit EIRP electromagnetic field electromagnetic interference electromagnetic resonance stylus Electronic Industries Alliance embedded MultiMediaCard embedded systems emergency calls EMI eMMC Ephemeris Data EPS EPS12V error correction coding eSATA ESD ESD precautions eSIM Ethernet Ethernet cable Ethernet jack Ethernet surge protector Ethernet switch exFAT external 2.5-inch hard drives F-connectors F-type failover fault tolerance FC connector feed assembly feed rollers feeder Ferrule Connector FHSS fiber fiber cable Fiber to the Home Fiber to the Node fiber-optic fiber-optic cables fiber-optic technology field devices FireWire firmware flash management flash memory Flex Cable form factor Fortinet FortiGate frequency-division multiplexing Fresnel zone friction feed front-panel audio header FTTH full backup full-array gap sensing GB/s Gbps general-purpose server geostationary earth orbit Gigabit Ethernet gigabits per second gigabytes per second GPS GPU grayscale ground station ground support equipment GSM Hard Disk Drives (HDDs)hard drive Hardware Security Module HBA HDD HDMI HEAD Healthcare IoT high-refresh high-voltage contacts HMI hot spare HSM HSPA+human-machine interface Hyper-Threading hypervisor I/O IC ICCID IDC IEEE IEEE 802.3af IEEE 802.3at iGPU impact printer IMSI in-plane switching industrial control systems Industrial IoT (IIoT)ink cartridge inkjet Institute of Electrical and Electronics Engineers insulation displacement connectors Intel VT-d Intel VT-x internet appliance internet connection type inverter IOMMU IoT IP phone IPP (Internet Printing Protocol)IPS glow ITX J-mount JPG ka-band ku-band KVM switch large data transfers latency LC LC connector LCD LED LED backlight LED indicators LED-backlit LCD legacy device legacy systems leo LGA LGA 1200 LGA 1700 light pulses line in line of sight line out line quality liquid cooling liquid crystal display liquid crystals Lithium-ion Lithium-Ion (Li-ion) Batteries Lithium-Ion Polymer (Li-Po) Batteries load balancer Local loop Logic Board logical volume loopback plug loose terminations LoRaWAN low earth orbit LPDDR LPDDR2 LPDDR3 LPDDR4 LPDDR5 Lucent Connector M.2 M.2 drive MAC MAC address Magnetic Field mAh mainframe computers managed switch management interface master terminal unit Max theoretical speed megabits per second memory memory channel memory controller memory effect MFP MHz MIC mic in micro-B Micro-USB microATX microchip microfilter microphone module microprocessors microSD Microsoldering midspan injectors milliampere-hour MIMO Mini DisplayPort connector mini PCs mini-ITX Mini-LED Mini-USB mirroring mmWave Mobile Hotspot MoCA filter Mode A Mode B modem modem-router modular keyboards modular power supply modulated signal Molex-to-SATA power monochrome Mopria motherboard mSATA MT/s MU-MIMO multi-feed multi-gigabit speeds multimode fiber multipart paper Multipath Errors multipoint connectivity N+1 redundancy NAS native driver Near Field Communication neighborhood cabinets Nest network cabling network device network interface Network Interface Card network interface cards Network Interface Device network printer network printing network switch network tap networking devices NFC NIC Nickel-Cadmium (NiCd) Batteries Nickel-Metal Hydride (NiMH) Batteries NICs NID nits noc noise cancellation non-removable (internal) batteries Non-Removable (Internal) Battery non-volatile memory NR NVMe NVMe SSD objective 2.7 OFDM oil and gas OLED ONT Operating System optical equipment optical light signals Optical Network Terminal optical signals organic light-emitting diode outdoor-rated Ethernet output rails Package-on-Package palm rejection panel antenna paper gap adjustment parity partial array self-refresh partition Passkey patch cable patch panel PC connector PCB PCI PCIe PCIe auxiliary power connectors PCIe slot PCIEX1 PCIEX16 PCs PD PDU Peer-to-Peer Mode performance bottleneck Peripheral Component Interconnect Peripheral Component Interconnect Express PGA phone line pickup rollers pigment-based ink PIN pixel density pixels platen roller PLCs plug-and-play PoE PoE injector PoE Plus PoE switch PoE+point-of-sale poor-quality cords PoP port 9100 port replicator portable SSDs POS POST power cycling power efficiency power grid power level Power over Ethernet power sourcing equipment power supply power supply unit powered devices predictive maintenance pressure sensitivity print driver print job print layer print path print port print processor print queue print server print settings Printer Control Language (PCL)printer driver printer memory printer pooling printer share name printer web page printhead PRL programmable logic controllers provider facilities prox card PSE PSU PSU connectors PUK punch-down blocks punchdown block punchdown tool PWM qam QPSK QR code quad-channel quadrature amplitude modulation radio communication radio frequencies radio frequency radio links radio waves Radio-Frequency Identification RAID RAID 0 RAID 1 RAID 10 RAID 5 RAID 6 rain fade RAM Random Access Memory RAW printing RDIMM Read & Execute read/write head Reader/Writer Mode rear I/O recovery time objective Reduced Instruction Set Computer redundancy Redundant Array of Independent Disks redundant power supply refresh rate region code region coding remote terminal units Removable Battery resistive touch RF RFID RG-59 RG-6 RG6 RGB RISC RJ-45 RJ11 RJ45 router RPM RSSI RTUs S.M.A.R.T.S/PDIF SAN SAS SATA SATA data SATA data cable SATA III SATA power Satellite satellite dish Satellite Geometry satellite links satellite modem SC SC connector SCADA SCADA server scaling screen resolution SD SDHC SDHC-only device SDXC sector radios Secure Boot Secure Element Secure Enclave Sensor Fusion sensor grid separation pads Serial (RS-232)Serial cables serial signaling server SFP SFX shared printing shared-bus signal bars SIM simultaneous multithreading single point of failure single-channel single-link single-mode fiber single-slot SiP Small Outline DIMM Small Outline Dual Inline Memory Module SMART smart card SMT SNR SO-DIMM SoC SODIMM software RAID soldered memory solid state drive Solid State Drives (SSDs)sound cards Speed Class spindle speed spudgers Square Connector SSD SSP ST ST connector standoffs static pressure status feedback storage Stratum 0 Stratum 1 Stratum 15 Stratum 16 Stratum 2 Stratum 3 striping subpixels Subscriber Connector superscope surge protection sustained read/write SVM Mode switch swollen battery System-in-Package system-on-a-chip system-on-chip T1 T2 T568A T568B Tachometer TDR tear bar Telecommunications Industry Association telecommunications room telephone company facilities television signals test jack thermal coating thermal pads thermal paste thermal printer thermal runaway thermal throttling thermal transfer printing throughput Thunderbolt Thunderbolt 1 Thunderbolt 2 Thunderbolt 3 Thunderbolt 4 TIA/EIA-568 TIFF tilt detection Time to First Fix time-domain reflectometry Timing Advance TN TN glow toner toner cartridge toner probe TOSLINK touch layer Tower Density TPM tractor-feed traffic signals transfer roller transparency mode Trilateration TRRS Trusted Platform Module TV tuner twisted nematic twisted pair twisted-pair copper cables Type 4 (v4)Type-A Type-B U.2 UDIMM UEFI UEFI update UHS ratings Ultra Physical Contact UNII UNII-1 UNII-2A UNII-2C UNII-3 UNII-5 UNII-6 UNII-7 UNII-8 Universal Flash Storage Universal Print Drivers unmanaged switch UPC connector UPS uptime US Naval Observatory USB USB 2.0 USB 2.0-grade cable USB 3.0 (USB 3.1 Gen 1)USB 3.1 Gen 2 USB 3.2 (2x2)USB 3.x USB ports USB standard USB Tethering USB-A USB-C USB-C connector USB-C OTG adapter USB-to-serial adapter USB4 UTM UTP VA VA glow VDSL very small aperture terminal VGA video capture video cards viewing angle virtual CPU virtual machines virtualization virtualization host virtualization support VM VM sprawl voice assistant integration voice device voltage regulator voltage regulator modules Volts AC VPN Concentrator VRM VRMs vsat VT-x wall jack wall plates WatchGuard Firebox watt-hour wattage rating Wear Leveling Count Wh whole-house splitter Wi-Fi analyzer Wi-Fi Direct wireless access point wiring closet WLAN module workstation write-protect switch x1 x16 x4 x64 x8 x86 Yagi antenna Z-Wave ZIF ZIF (Zero Insertion Force) connector ZIF connector Zigbee

Network1

header analysis

Networking251

3G 4G 4G LTE 802.11 A record AAAA record ACK ACMA ADSL AFP API APIPA APN authoritative name server Automatic Private IP Addressing backhaul bandwidth bandwidth usage broadband internet broadband service broadcast domain broadcast traffic captive portal CDMA2000 Cell ID cellular network Central Office CIFS cisco ios client request client-server model CNAME record computer networks data caps data packets datagram default gateway destination port destination unreachable dhclient DHCP DHCP relay agent DHCP reservation DHCP server DHCP starvation DHCPACK DHCPDISCOVER DHCPNAK DHCPOFFER DHCPREQUEST dial-up Digital Subscriber Line DNS DNS cache DNS hierarchy DNS over HTTPS DNS over TLS DNS propagation DNS resolution DNS server DOCSIS 3.1 Domain Name System downstream downstream communication Dynamic Host Configuration Protocol Dynamic IP Addressing email traffic Ethernet frame ETSI FCC fiber internet Fiber to the Building file transfer protocol five-tuple fixed wireless FTP FTTB FTTN gateway handoff handover hotspot HSPA HTTP HTTP status codes ICMP IMAP Internet Protocol internet protocol networks Internet Protocol version 4 Internet Protocol version 6 Internet Service Provider IP ip address IP configuration IP header IP helper IP-based virtual hosting ipconfig IPv4 IPv6 ISP LAN Layer 2 lease time leased lines legacy networks load balancing algorithm local area network LTE LTE data LTE-Advanced MAC address table MAC learning MAN Mbps Media Access Control mesh networking Metro Ethernet MPLS MST MTU multicast MX record NAT neighborhood congestion NetBIOS NetBT netsh network address translation network layer network operations center network outage network path Network Policies Network Technology Network Time Protocol next hop NFS NFSv4 nslookup NTP NTP Pool Project OFDMA OSI model packet data packet filtering packet loss PAN PAN Profile peer-to-peer Personal Area Network ping point-to-multipoint point-to-point POP3 port configuration port forwarding port number port security PPP private IP address provider's data network proxy PTR record public IP address public network QoS Quality of Service radio access network RADIUS recursive DNS resolver roaming rogue DHCP server root DNS server root zone routing routing protocols routing table rural broadband installs satellite internet SDSL Second-Level Domains share name Simple Network Time Protocol SMB SMB 3.0 SMTP SNMP SNTP source port SPF record SSID STARTTLS Static IP Addressing STP Subdomains subnet subnet mask Symmetric DSL SYN SYN-ACK syslog server TCP TCP header TCP port 1433 TCP/IP telnet Tethering TFTP three-way handshake time.apple.com time.google.com time.windows.com TLD server TLDs Top-Level Domains tracert traffic management traffic management systems traffic segmentation transmission control protocol transport layer TXT record UDP UDP header UDP port 123 UMTS UNC UNC path Unlicensed National Information Infrastructure upstream upstream communication user datagram protocol Very-high-bit-rate DSL Virtual LAN Virtual Machine virtual private network VLAN VoIP VoLTE WAN Wi-Fi Wi-Fi calling Wi-Fi Hotspot wide area network WiMAX WINS Wireless Internet Service Providers WISP WLAN

Networking, Security1

VPN

Operating Systems28

Programming13

C#C$HTML Java MDA Node.js operators PHP programming languages PUT Python Ruby state table

Security123

2FA 802.1X authentication AAA ABAC access control list admin permissions advanced encryption standard aes anti-malware antivirus app password application control at-rest encryption attachment scanning audit logs Authentication Authorization Biometric Authentication BitLocker blacklist brute force attacks CA CCPA Certificate Authority Certificate-Based Authentication Cisco Email Security cybersecurity data exfiltration data loss prevention DDoS DDoS attacks defense in depth denial of service directory traversal distributed denial-of-service DKIM DKIM record DLP DMARC DMARC record DNS cache poisoning DNS hijacking DNS spoofing DNS tunneling DNSSEC DoH DoT EAP-TLS Encryption Policies federated identity Firewall GDPR HMAC-based One-Time Passwords HOTP HTTPS IDS/IPS in-transit encryption intrusion detection and prevention IPS KDC Kerberos malware man-in-the-middle attack mantraps MFA Microsoft Defender for Office 365 Mimecast monlist command multi-factor authentication network security next-generation firewall NIST NTP amplification attacks OAuth OTP Password-Based Authentication permissions PGP phishing Proofpoint ransomware RBAC reputation filtering rule base S/MIME sandboxing security information and event management sender authentication SFTP siem signature databases single sign-on SonicWall Sophos UTM spam spam gateway SPF spoofing SQL injection SSH SSL SSL/TLS certificate SSO stateful inspection stateful packet inspection TACACS+TGT time-based attack vectors Time-based One-Time Passwords TLS TLS/SSL Token-Based Authentication TOTP two-factor authentication unified threat management user permissions vulnerabilities vulnerability Windows Firewall WPA2 WPA2/WPA3-Enterprise WPA3 XSS