Tech+ key terms

A number system that uses only two digits, 0 and 1, to represent every piece of data and every instruction inside a computer.

A base-16 number system that uses the digits 0-9 and the letters A-F; it gives people a shorter, easier way to read long binary values such as memory addresses and color codes.

The smallest unit of digital data, holding a single binary value of either 0 or 1; eight of them combine to form one byte.

A group of eight bits handled as one unit; it is the usual measure of file and storage size and can hold one character of text in common encodings.

The field of building computer systems that perform tasks normally requiring human intelligence, such as understanding language, recognizing images, or making decisions.

A branch of artificial intelligence in which programs improve at a task by learning patterns from data instead of following rules written by hand for every case.

A structured process for solving technical problems: identify the problem, form a theory of cause, test it, plan and apply a fix, verify the result, and document what was done.

The processor chip that carries out instructions by fetching, decoding, and executing the calculations and logic that make programs run.

Short-term working memory that holds the programs and data the processor is using right now; everything in it is lost when power is turned off.

Running several isolated operating systems, called virtual machines, on one physical computer so that hardware is used more efficiently.

Software that creates and runs virtual machines, dividing a host computer's processor, memory, storage, and network connections among them so each guest acts like its own computer.

Delivering computing resources such as servers, storage, and software over the internet on demand, with usage metered and billed as you go.

A numeric label given to a device on a network so that data can be addressed to it and routed to the right place.

The Domain Name System is a service that translates easy-to-remember names such as example.com into the IP addresses computers use to reach each other.

A network service that automatically supplies IP addresses and related settings to devices when they connect, instead of someone configuring each one by hand.

A device that forwards data packets between different networks, choosing a path so traffic reaches its correct destination.

A device that connects the devices on one local network and forwards each frame only to the port where the intended destination is attached.

Everyday physical objects that contain sensors and network connections and exchange data over a network with little or no direct human involvement.

The main software on a computer that starts the machine, manages hardware and files, runs applications, and provides a way for users to interact with it.

Programs written to help a user complete a specific task, such as writing a document, browsing the web, or editing a photo.

A way of using a computer through visual elements such as windows, icons, and menus, instead of typing commands at a text prompt.

A finite, ordered set of steps that solves a problem or completes a task, written so a person or a computer can carry it out.

A plain-language sketch of program logic that mixes informal English with code-like structure, used to plan an algorithm before real code is written.

A named storage location in a program that holds a value which can change while the program runs, so code can store, read, and update it.

A programming structure that repeats a block of statements until a condition is met or a set number of passes has been made.

A named, reusable block of code that performs a task, can accept inputs, and may return a result to the part of the program that called it.

A system that records changes to files over time so developers can review history, compare versions, and undo or combine edits.

An organized collection of data stored so it can be searched, updated, and retrieved efficiently, usually managed by dedicated database software.

A database that stores data in tables of rows and columns and links one table to another through matching key values.

A column, or set of columns, whose value uniquely identifies each row in a table, so no two rows can have the same key.

A column in one table that holds a primary key value from another table, creating a link between the two tables.

Structured Query Language: a standard language used to create, read, update, and delete data in relational databases and to define their structure.

The process of proving an identity, usually by presenting something you know, something you have, or something you are.

The process of deciding what an authenticated user or program may access or do, based on assigned permissions, roles, or rules.

Signing in with two or more different kinds of evidence, such as a password plus a code from a phone, so a stolen password alone is not enough.

Converting readable data into scrambled ciphertext with a key, so that only someone holding the correct key can turn it back into plaintext.

Software written to damage, disrupt, or gain unauthorized access to a system, including viruses, worms, ransomware, spyware, and trojan horses.

A scam that pretends to be a trusted person or company to trick people into revealing passwords or clicking harmful links, often through email.

A security control that inspects network traffic and allows or blocks it by rule, forming a barrier between a trusted network and an untrusted one.

The practice of giving each user and program only the access needed to do its job, and no more, to limit damage from mistakes or attacks.