2-factor authentication#

2FA is a means for a computer user to identify themself and authenticate using both something they know (usually a password) with something they have (often a phone or keychain with changing digits on it).


A single one or zero; the fundamental digit in the binary number system.


Eight bits together, representing a number between 0 and \(2^8-1\) or 255


Computer graphics represented as a connected grid of pixels of different colors that make up an image. Used often to represent photographs on computers.

Cascading Style Sheets#

A system of text files that define the look and feel of a web page separately from the files and/or data that make up the content of the page.


A content management system is Web-based software that assists in building and maintaining websites in user-friendly ways.


Always-available computer servers running on the internet. Often used as an alternate place to store files or e-mails rather than on a local hard disk drive.

Command line#

The interface on many computer systems that allows the user to enter text commands to be processed. Infamous for looking hacky but actually being extremely expressive and useful.

Central Processing Unit#

The CPU is the “brain” of a computer, it’s a microprocessor that crunches all the numbers. Made of billions and billions of little transistors etched onto a silicon wafer.

Dark web#

Any part of the internet that isn’t readily available for browsing by the public. Technically includes your friends’ e-mails since not everyone is authorized to see them. Typically used in practice to refer to the black market networks running alongside more legitimate services in The Onion Router.


A computer system designed to receive, store, and retrieve large amounts of information from multiple concurrent other computer systems.


The Domain Name System is a “phonebook” for computer networks that maps readable names like to computer-usable IP addresses like


Electronic Frontier Foundation is a nonprofit defending digital privacy, free speech, and innovation.


The process of hiding information from prying eyes on network or elsewhere using math. Can also validate that information was sent unchanged from a particular individual.


Gnu’s Not Unix (GNU) (recursive acronym) is a free-software collaboration project that started in 1983 and continues to this day. Many free, open-source tools are developed under the GNU umbrella.


A Graphical User Interface uses a monitor and a mouse or touchscreen to provide a visual-based experience in using a computer program rather than a purely text-driven environment. Windows and macOS are GUI OSs, while DOS was not (if you recall DOS).

Hard drive#

The device in a computer that stores information like documents, photos, programs, and so on for long periods of time. Contrast with RAM (see Memory).

IP address#

An Internet Protocol address defines where a computer is on a computer network, similar to a street address in real life. It is numerical, either four numbers between 0 and 255 separated by periods (IPv4) or eight groups of four hexadecimal digits separated by colons (IPv6). All domain names and other human-readable network locations are mapped to IP addresses via DNS.


An Internet Service Provider is a company you pay to deliver a connection to the public internet. Examples include Comcast, CenturyLink, Charter, etc.


A document typesetting and publishing system that separates content from presentation.

Lightweight markup language#

A markup language with an intentionally-simple syntax, often to accommodate rapid creation by a human writer.

Linear regression#

The process of finding the equation of a line that best fits a given set of data points.


An open-source operating system that powers many servers that make up the internet, all Android smart-phones, all of the top 500 largest supercomputers on Earth, and a small but growing number of PCs.


A proprietary operating system made by Apple and used on Apple computers and iPhones.

Markup language#

A way to express something to a computer using a text file with special text-based annotations. For instance, while italics cannot be represented directly in a pure text file, a word could be indicated as italicized by surrounding it in in <i> tags. Markup languages are used often for rich data exchange (e.g. HTML and XML).


Hardware that can store large chunks of information on a computer for some period of time. Memory is typically used for Random Access Memory (RAM), which is a short-lived fast-acting memory. There’s also hard-drive memory which is slower, larger, and cheaper.

Network Attached Storage#

A NAS is a bank of large hard drives that are made available on a network, often used for backups of photos and videos.


Random information present on any analog signal such as the hiss on the radio or the snow on old TVs

Onion router#

A web-browsing technology that offers increased anonymity and security over normal browsing. It hides the web pages you’re browsing from the infrastructure and hides your place of origin from the web pages you browse.

Operating system#

An OS is a set of software that runs a computer. It interacts with all hardware and provides the environment in which other programs run. Examples are Windows, macOS, and Linux.

Package manager#

A program that can go out on the internet and find a different program, download it, install it, configure it, and (later, if desired) uninstall it. These pre-date app stores but are very similar in concept. These allow for easy program management, often though at least nominally more secure channels than random downloads. Each OS has its own package managers.

Password manager#

A program or service that stores various passwords for various services in one place. It also has facilities for generating random passwords to avoid the problems of password-reuse.


Writing a sequence of operations for a computer to perform. The process of creating software.

Regular expressions#

A general pattern representing some combination of letters, numbers, punctuation, and other characters that is used for advanced searching and replacing in text and data processing.


A network component that receives packets and forwards them to a client or other network that it knows about but perhaps the sender does not (and vice versa).

Secure Shell (SSH)#

A means for accessing the command line of a computer that’s connected to you by a network that maintains strong security along the network as commands and responses are passed back and forth.

Static site generator#

A program or system that converts lightweight markdown language code and images into a full HTML website. It’s effectively a lightweight CMS.

Text editor#

A program that views and modifies text files.

Text file#

A universal file that only contains sequences of characters without any embedded information about font, style, etc. These are very useful and fundamental as an interface file between various steps of data processing, publishing, programming, etc.

Top-level domain#

A TLD is the suffix of a domain name like .com or .edu or even .horse.

Vector graphics#

Computer graphics defined by mathematical equations rather than grids of pixels. For certain types of images (e.g. icons, logos) they are nice because they use very few bits but can be zoomed in on infinitely. Contrast with Bitmaps.

Virtual machine#

A computer program that emulates the hardware of a different computer system.


A Virtual Private Network is a technology that securely connects through the public internet to servers you are specially authorized on. Used frequently for businesses, allowing employees to connect to corporate intranet resources like shared drives while away on travel. Also offered as a commercial service to help add network security and privacy for consumers.


Virtual Studio Technology is a specification that defines how a large set of software plugins work together while composing music on a computerized studio.


A proprietary operating system made by Microsoft that runs on most consumer and office PCs.