Glossary

**Z-Score**: A statistical measure that describes a data point's relationship to the mean of a group of values, expressed as the number of standard deviations away from the mean; often used in hypothesis testing and outlier detection.

**Zero-Day**: A term used in cybersecurity to describe a vulnerability in software that is unknown to the vendor and has no patch available, often exploited by attackers before it is discovered and fixed.

**Zero-Shot Learning**: A machine learning paradigm where a model is trained to recognize objects or perform tasks without having seen any examples from the target class during training, often by leveraging semantic information.

**Zero-Centering**: A data preprocessing technique where the mean of each feature is subtracted from the data, resulting in a dataset with a mean of zero, commonly used in machine learning to improve training stability.

**Zero-Inflated Model**: A statistical model used for count data that has an excess of zero counts, combining a count model (like Poisson or negative binomial) with a binary model to account for the excess zeros.

**Zero-Sum Game**: A concept in game theory where one participant's gain or loss is exactly balanced by the losses or gains of the other participants, often used in economics and strategic decision-making.

**Z-Test**: A statistical test used to determine whether there is a significant difference between sample and population means, assuming the data follows a normal distribution and the population variance is known.

**Z-Order Curve**: A space-filling curve that maps multidimensional data to one dimension while preserving locality, often used in spatial indexing and databases to improve query performance.

**Zoom Lens Model**: A model in visual perception and cognitive psychology that describes how attention can be focused like a zoom lens, narrowing in on a specific area while filtering out surrounding information.

**Zigzag Iterator**: An algorithm or data structure that iterates through elements in a zigzag pattern, often used in matrix traversal or scenarios where alternating order is required.

**Zero-Padding**: A technique used in convolutional neural networks where extra pixels with zero values are added to the input image, allowing for control over the spatial dimensions of the output feature maps.

**Zero-Suppression**: The process of removing or hiding zero values in data, often used in data visualization and reporting to make the data easier to read and interpret.

**Zipf's Law**: An empirical law that describes the frequency distribution of words in natural language, where the frequency of any word is inversely proportional to its rank in the frequency table, often observed in linguistic and social phenomena.

**Z-Normalization**: A normalization technique where data is scaled so that it has a mean of zero and a standard deviation of one, often used in time series analysis to compare sequences with different scales.

**Zone of Proximal Development (ZPD)**: A concept from educational psychology that refers to the difference between what a learner can do without help and what they can achieve with guidance, often used to tailor learning interventions.

**Z-Transform**: A mathematical tool used in signal processing and control systems to analyze and manipulate discrete-time signals, often used to convert signals from the time domain to the frequency domain.

**Zero-Noise Extrapolation (ZNE)**: A technique used in quantum computing to mitigate errors by extrapolating results from different noise levels to estimate what the result would be with zero noise.

**Zoning**: A method used in image processing and pattern recognition where an image or pattern is divided into zones or regions for feature extraction or classification, often used in OCR and handwriting recognition.

**Zeno's Paradox**: A philosophical paradox that questions the concept of motion and division, often used in discussions about convergence and the limits of sequences in mathematical analysis.

**Zero-Touch Deployment**: A method in IT and software development where systems or applications are deployed automatically with minimal or no manual intervention, often used in cloud computing and DevOps practices.

**Zero-Overhead Abstraction**: A principle in programming languages where abstractions (like classes or functions) incur no additional runtime cost compared to lower-level code, often emphasized in languages like C++.

**Zero-Latency**: The concept of achieving instant or near-instant response times in computing and communication systems, often used in real-time applications like gaming, financial trading, and virtual reality.

**Zone Routing Protocol (ZRP)**: A hybrid routing protocol used in mobile ad hoc networks that combines proactive and reactive routing strategies to improve efficiency and scalability.