| ACK | ACKnowledgement |
| AI | Artificial Intelligence |
| ALSA | Advanced Linux Sound Architecture |
| AMOLED | Active-Matrix Organic Light-Emitting Diode |
| ANSI | American National Standards Institute |
| API | Application Programming Interface |
| ARM | Advanced RISC Machines |
| ARPA | Advanced Research Projects Agency |
| ARPANET | Advanced Research Projects Agency Network |
| ASCII | American Standard Code for Information Interchange |
| ASP | Active Server Pages (Microsoft) |
| ATA | Advanced Technology Attachment |
| ATAPI | Advanced Technology Attachment Packet Interface |
| ATM | Asynchronous Transfer Mode |
| AWS | Amazon Web Services |
| CA | Certificate Authority |
| CAD | Computer-Aided Design |
| CAPTCHA | Completely Automated Public Turing test to tell Computers and Humans Apart |
| CD-ROM | CD Read-Only Memory |
| CD-RW | CD-Rewritable |
| CGI | Computer-Generated Imagery |
| CIDR | Classless Inter-Domain Routing |
| CIFS | Common Internet Filesystem |
| CLI | Command Line Interface |
| CMOS | Complementary metal–oxide–semiconductor |
| COBOL | Common Business-Oriented Language |
| CORBA | Common Object Request Broker Architecture |
| CP/M | Control Program/Monitor, an old OS |
| CPU | Central Processing Unit |
| CRLF | Carriage Return line feed, used on Micrososft machines |
| CR | Carriage Return, used on Linux machines |
| CRT | Cathode-ray tube |
| CS | Cable Select, used on UART chips |
| CSS | Cascading style sheets |
| DARPA | Defense Advanced Research Projects Agency |
| DB | Database |
| DDoS | Distributed Denial of Service, a webpage attack simultaneously from multiple IP addresses |
| DEC | Digital Equipment Corporation |
| DHCP | Dynamic Host Configuration Protocol, used assign automatically an IP address on the LAN |
| DHTML | Dynamic Hypertext Markup Language |
| DIMM | Dual Inline Memory Module |
| DIP | Digital Instrumentation Programmer, often includes a rippon strip of wires connected to a device that plugs into a Programmer device that in tern uses a USB-B to USB-A cable to connect to a PC with software to read and program the IC. |
| DMI | Direct Media Interface |
| DMZ | Demilitarized Zone, used to expose a web server directly to the WAN |
| DN | Distinguished Name |
| DNS | Domain Name System |
| DoS | Denial of Service, a recurring webpage attack from a single IP address |
| DOS | Disk Operating System (Microsoft) |
| DR-DOS | Digital Research – Disk Operating System, an open source for DOS |
| DRAM | Dynamic Random-Access Memory |
| DSL | Digital Subscriber Line, an old system for connecting to the internet through telephone wires |
| DSN | Database Source Name |
| DVD-R | DVD-Recordable |
| DVD-ROM | DVD-Read-Only Memory |
| DVD-RW | DVD-Rewritable |
| DVD | Digital Versatile Disc or Digital Video Disc |
| DVI | Digital Visual Interface |
| E-mail | Electronic mail |
| EAP | Extensible Authentication Protocol |
| EEPROM | Electronically Erasable Programmable Read-Only Memory |
| EFI | Extensible Firmware Interface |
| EIDE | Enhanced IDE |
| EISA | Extended Industry Standard Architecture |
| EMACS | Editor MACroS, a common text editor |
| EOF | End of File |
| EOL | End of Line |
| EOM | End of Message |
| EPON | Ethernet Passive Optical Network, used in fiberoptics |
| EPROM | Erasable Programmable Read-Only Memory |
| eSATA | external SATA |
| EULA | End User License Agreement |
| FAT | File Allocation Table |
| FAQ | Frequently Asked Questions |
| FDC | Floppy-Disk Controller |
| FDDI | Fiber Distributed Data Interface |
| FET | Field Effect Transistor |
| FFC | Flat Flexible Circuit, a ribbon cable used to connect an HAT to a Raspberry Pi via a PCIe connector. |
| FIFO | First In First Out |
| FLAC | Free Lossless Audio Codec |
| FLOPS | FLoating-Point Operations Per Second |
| FORTRAN | Formula Translation, an old OS |
| FOSS | Free and Open-Source Software, Linux |
| FPU | Floating-Point Unit |
| FS | File System |
| fsck | File System Check, a Linux command |
| FTP | File Transfer Protocol, now replaced with SSH |
| FQDN | Fully Qualified Domain Name, in the form www.example.com |
| HAL | Hardware Abstraction Layer, not from 2001 Space Odyssey |
| HAT | Hardware Attached on Top, usually for Raspberry Pi |
| HDD | Hard Disk Drive, an old spinning hard drive, 3.5” |
| HDMI | High-Definition Multimedia Interface, a standard monitor inferface |
| HF | High Frequency |
| HFS | Hierarchical File System |
| HP | Hewlett-Packard |
| HTML | Hypertext Markup Language |
| HTTP | Hypertext Transfer Protocol |
| HTTPd | Hypertext Transport Protocol Daemon |
| HTTPS | HTTP Secure |
| HTX | HyperTransport eXpansion |
| I/O | Input/output |
| I²C | Inter-Integrated Circuit, a type of communication protocol |
| IANA | Internet Assigned Numbers Authority, who track IP addresses |
| IBM | International Business Machines |
| IC | Integrated Circuit |
| ICANN | Internet Corporation for Assigned Names and Numbers |
| ICH | I/O Controller Hub |
| ICMP | Internet Control Message Protocol |
| IDE | Integrated Development Environment, used for programming |
| IDE | Integrated Drive Electronics |
| IE | Internet Explorer, now succeeded by the Edge browser (Microsoft) |
| IEC | International Electrotechnical Commission |
| IEEE | Institute of Electrical and Electronics Engineers |
| IMAP | Internet Message Access Protocol |
| IoT | Internet of Things |
| IP | Internet Protocol, the address in the form 192.168.1.1 for a LAN router. |
| IPP | Internet Printing Protocol |
| IPv4 | Internet Protocol version 4 |
| IPv6 | Internet Protocol version 6 |
| IPX | Internetwork Packet Exchange |
| IRC | Internet Relay Chat |
| IRQ | Interrupt Request, used by the computer hardware, for example the IRQ used for the monitor |
| IS | Information Systems |
| ISA | Industry Standard Architecture |
| ISA | Instruction Set Architecture |
| ISAM | Indexed Sequential Access Method |
| iSCSI | Internet Small Computer System Interface |
| ISDN | Integrated Services Digital Network |
| ISO | International Organization for Standardization |
| ISP | Internet Service Provider, a company such as Roadrunner or Spectrum |
| IT | Information Technology |
| LAMP | Linux Apache MySQL PHP, minimum standard for a web server |
| LAN | Local Area Network |
| LBA | Logical Block Addressing |
| LCD | Liquid Crystal Display |
| LCOS | Liquid Crystal On Silicon |
| LDAP | Lightweight Directory Access Protocol |
| LF | Line Feed, used on Linux as \n |
| LIB | LIBrary |
| LIFO | Last In First Out |
| LILO | Linux Loader |
| LISP | LISt Processing |
| LSB | Least Significant Bit |
| LTE | Long Term Evolution, used for Linux distributions that will receive security updates for at least 5 years |
| LVM | Logical Volume Management, a method to group partitions without exceeding the maximum number of 4 per HDD or SSD |
| LZW | Lempel-Ziv-Welch, a type of file system |
| MAC | Media Access Control |
| MAPI | Messaging Application Programming Interface |
| Mb | Megabit |
| MB | Megabyte |
| Mbps | Megabits per second |
| MBR | Master Boot Record |
| ME | Microsoft Edge, the browser that replaced Internet Explorer (Microsoft) |
| MIDI | Musical Instrument Digital Interface, used to connect a keyboard to the computer |
| MIME | Multipurpose Internet Mail Extensions |
| MIMO | Multiple-Input Multiple-Output |
| MIPS | Million Instructions Per Second |
| MMU | Memory Management Unit |
| MoBo | Motherboard |
| MOSFET | Metal Oxide Semiconductor Field Effect Transistor, often several are used near the Power Supply Unit to level off the voltage. |
| MOV | Apple QuickTime Multimedia File |
| MPEG | Motion Pictures Experts Group |
| MS-DOS | Microsoft DOS |
| MS | Microsoft |
| MSB | Most Significant Bit |
| MSDN | Microsoft Developer Network |
| MSI | Microsoft Installer |
| MSN | Microsoft Network |
| MTU | Maximum Transmission Unit |
| MU | Memory Unit |
| NAS | Network-Attached Storage |
| NAT | Network Address Translation, used to translate traffic from WAN to LAN |
| NetBIOS | Network Basic Input/Output System, used to display computer names to the network |
| NetBT | NetBIOS over TCP/IP |
| NFS | Network File System |
| NIC | Network Interface Controller, used to connect the RJ-45 cable to the LAN |
| NIST | National Institute of Standards and Technology |
| NLP | Natural Language Processing |
| NOP | No Operation |
| NPU | Network Processing Unit |
| NS | Netscape, an old browser |
| NT | New Technology |
| NTFS | NT Filesystem (Microsoft) |
| NVRAM | Non-Volatile Random-Access Memory |
| OASIS | Organization for the Advancement of Structured Information Standards |
| OCR | Optical Character Recognition |
| ODBC | Open Database Connectivity |
| OEM | Original Equipment Manufacturer, hardware supplied by DELL, HP, etc. |
| OLE | Object Linking and Embedding |
| OLED | Organic Light Emitting Diode |
| ONU | Optical Network Unit, used to connect fiberoptics WAN to ethernet LAN. |
| OO | OpenOffice, a suite of software from Sun Microsystems (Open Source) |
| OOM | Out Of Memory |
| OOo | OpenOffice.org |
| OOP | Object-Oriented Programming |
| OS | Operating System |
| OSDN | Open Source Development Network |
| OSI | Open Source Initiative |
| OSI | Open Systems Interconnection |
| PARC | Palo Alto Research Center |
| PATA | Parallel ATA, used for floppy discs with an IDE connector, predates SATA |
| PC-DOS | Personal Computer Disc Operating System, a command driven OS used by Microsoft prior to 1985. |
| PC | Personal Computer |
| PCB | Printed Circuit Board |
| PCI | Peripheral Component Interconnect |
| PCIe | PCI Express, used to connect graphics cards, NVMe SSDs, etc. I comes in 1, 2, 4, 8, 16 channels. |
| PCM | Pulse-Code Modulation |
| PCMCIA | Personal Computer Memory Card International Association, an old connector for memory chips used in digital cameras, etc. |
| PDA | Personal Digital Assistant, predates the Blackberry and the smart devices in use today |
| PDF | Portable Document Format |
| PERL | Practical Extraction and Reporting Language, an old programming language |
| PHP | Hypertext Preprocessor, a programming language used in open source web browsers |
| PID | Process ID |
| PING | Packet Internet Gopher, used to send CMP packets for testing purposes |
| Pixel | Picture element |
| PKCS | Public Key Cryptography Standards |
| PKI | Public Key Infrastructure |
| PLC | Programmable Logic Controller |
| PLCC | Plastic Leadless Chip Carrier, used to pull ICs off a PCB |
| PNG | Portable Network Graphics |
| PnP | Plug-and-Play |
| PoE | Power over Ethernet, where a device can be powered by the data cable rather than a separate adapter |
| POP3 | Post Office Protocol v3 |
| POSIX | Portable Operating System Interface, formerly IEEE-IX |
| POST | Power-On Self Test, first used as a PC or device boots up. |
| PPM | Pages Per Minute |
| PS | PostScript |
| PS/2 | Personal System/2 |
| PSU | Power Supply Unit, used to power a PC |
| RAD | Rapid Application Development |
| RAID | Redundant Array of Independent Disks, used to configure two storage devices as one with enhanced error protection |
| RAM | Random-Access Memory |
| RC | Region Code, used to append telephone numbers: 1=US, 2=Europe, 3=Southeast Asia, 4=Latin America, 5=Africa, 6=China, 7=DVD, 8=aircraft, cruise ships and spacecraft |
| RC | Release Candidate |
| RDBMS | Relational Database Management System such as mysql |
| RDP | Remote Desktop Protocol, used to connect a GUI to a remote machine |
| regex | Regular Expression such as [A-z], [0-9], etc |
| RGB | Red, Green, Blue |
| RHEL | Red Hat Enterprise Linux |
| RHL | Red Hat Linux, a licensed version of Linux |
| RIP | Raster Image Processor |
| RIP | Routing Information Protocol |
| RISC | Reduced Instruction Set Computer such as an ARM or RISC-V CPU |
| RLE | Run-Length Encoding |
| rmdir | remove directory, linux command |
| RMS | Richard Matthew Stallman, an encryption algorithm |
| ROM | Read-Only Memory |
| RPC | Remote Procedure Call |
| RPM | Redhat Package Manager |
| RSA | Rivest Shamir Adleman, an encryption algorithm |
| RSS | Radio Service Software |
| RSVP | Resource Reservation Protocol |
| RTC | Real-Time Clock |
| RTF | Rich Text Format |
| RTS | Ready To Send |
| SATA | Serial ATA |
| SCSI | Small Computer System Interface |
| SDK | Software Development Kit |
| SDRAM | Synchronous Dynamic Random-Access Memory |
| SFP | Small Form-factor Pluggable device, a fiberoptic interface that connects to a router or a computer.; 850 nm laser to 10G Base ethernet |
| SHA | Secure Hash Algorithm, as in sha256 |
| SIMM | Single Inline Memory Module |
| SISO | Single-Input and Single-Output |
| SMB | Samba, a network protocol used to communicate from Linux to Microsoft. |
| SMB | Server Message Block |
| SMBIOS | System Management BIOS |
| SNMP | Simple Network Management Protocol |
| SNTP | Simple Network Time Protocol |
| SO-DIMM | Small Outline DIMM |
| SoC | System-on-a-Chip |
| SOP | Small Outline Package, an IC mounted on a PCB such as a Flash EPROM: SOP8, SOP16, SOP24, etc. |
| SPARC | Scalable Processor Architecture |
| SPI | Serial Peripheral Interface, a bus that communicates between a flash-ROM and a controller IC |
| SQL | Structured Query Language |
| SRAM | Static Random-Access Memory |
| SSD | Solid-State Drive |
| SSH | Secure Shell, used to log on remotely to a server. |
| SSL | Secure Socket Layer, used for encryption. |
| su | superuser, used to gain root access in bash. |
| SUSE | Software und System-Entwicklung, a Linux OS. |
| SVG | Scalable Vector Graphics |
| SVGA | Super Video Graphics Array |
| TAPI | Telephony Application Programming Interface |
| TB | TeraByte |
| TCP | Transmission Control Protocol |
| TCP/IP | Transmission Control Protocol/Internet Protocol |
| TI | Texas Instruments |
| TIFF | Tagged Image File Format |
| TLD | Top-Level Domain: com, edu, org, etc. |
| TLS | Transport Layer Security |
| tmp | temporary |
| TRON | Trace On |
| TRSDOS | Tandy Radio Shack–Disk Operating System, old |
| TTF | TrueType Font (Microsoft) |
| TTL | Time To Live |
| TTL | Transistor-Transistor Logic |
| TTS | Text-to-Speech |
| TTY | Teletype |
| UAC | User Account Control |
| UART | Universal Asynchronous Receiver/Transmitter |
| UDP | User Datagram Protocol |
| UEFI | Unified Extensible Firmware Interface |
| UI | User Interface |
| UMA | Upper Memory Area |
| UMB | Upper Memory Block |
| UML | Unified Modeling Language |
| UNC | Universal Naming Convention |
| UNIVAC | Universal Automatic Computer (By MKS) |
| UPS | Uninterruptible Power Supply, used during a storm if the power should go out |
| URI | Uniform Resource Identifier |
| URL | Uniform Resource Locator |
| URN | Uniform Resource Name |
| USB | Universal Serial Bus |
| usr | User System Resources |
| UTC | Coordinated Universal Time |
| UTP | Unshielded Twisted Pair |
| UUID | Universally Unique Identifier |